Prehistoric Plants

prehistoric plants

Download: Prehistoric Plants Lesson Plan

Overview: Plants make all other life on earth possible, and they always have! Like the great reptiles that used to roam the earth, many prehistoric plants have disappeared, but some of the green species that grew millions of years ago still thrive today. Through this lesson, students will learn about three distinct types of plants (ferns, gymnosperms and angiosperms) and how plants have changed over millions of years.

Grade Level/Range: 6- 8th grade


Students will learn common characteristics of ferns, gymnosperms and angiosperms through observation and how their characteristics help them to adapt differently to their environments.

Time: 1 hour


  • Samples of fern plant parts, including leaves (look for some with sporangia on the back), fiddleheads, and if possible prothallus (the first stage of growth of a fern is represented by translucent, heart-shaped plants – this may be tricky to find, but you can try growing your own).  You can collect from both indoor and outdoor ferns.
  • Samples of gymnosperm plant parts, including leaves/needles and a cone with seeds. Collect these from common plants such as pine, fir, and spruce trees and junipers.
  • Samples of angiosperm plant parts, including leaves and fruits with seeds. Collect from fruit trees and common landscape trees like maples, sweet gum, and oaks.
  • Plant Comparison Chart (below)

Background Information:

Who isn’t intrigued by dinosaurs? The mystery behind their lives and extinction engages the imagination of young and old alike, inviting visions of a world dominated by huge lizards. Using fossil evidence, researchers use science and imagination to interpret the stories of these magnificent creatures. Like the great reptiles, many prehistoric plants have disappeared, but some of the green species that grew millions of years ago still thrive today.

The earliest plants actually prepared the path for animals evolve. They harnessed the sun’s energy for creating their own food from water and carbon dioxide via photosynthesis, releasing oxygen as a byproduct. Plants form the foundation of every food chain. We know that they were an important part of the dinosaurs’ world and that they evolved significantly during the mighty lizards’ 80-million-year reign. But if plants don’t have bones to leave behind, how do we know which plants were around back then?

Scientists track the appearance and evolution of plant life by analyzing fossils, but they haven’t found many specimens because plants decompose so quickly. Fortunately, nature has its ways of recording history. Plant fossils are formed when plant matter (such as stems, leaves, roots, spores, seeds, or fruits) is protected from rapid decomposition by being covered with sediment such as clay, mud, sand, and volcanic ash. The resulting fossils vary:

  • Some contain plant matter that has not fully decomposed, leaving trace amounts of tissue or a layer of carbon.
  • Others contain no actual plant remains, but the surrounding sediment retained an imprint of the plant material.
  • Some are preserved as a sculptural likeness of plant material via the process of petrification. Minerals in solution replace the water in cell cavities and then precipitate, forming stone. (Petrified wood is the result of entire tree trunks and limbs preserved in this manner.)
  • Scientists also obtain information about prehistoric plants from dinosaur coprolites  (AKA fossilized dinosaur poop) and from remains found in the stomach cavities of dinosaur skeletons!

By studying these various types of fossils, scientists have pieced together the following record of the appearance of terrestrial plants:

Era Period Million Years Ago (mya) Plant Life on Land
Precambrian 3800? to 543
Paleozoic 543 to 248 The first land plants appeared, including mosses, horsetails (~400 mya) and ferns (~350 mya).
Mesozoic Triassic 248 to 206
Jurassic 206 to 144 First seed-bearing plants emerged, including conifers such as bald cypress, ginkgos, and cycads (~200 mya)
Cretaceous 144 to 65 True flowering plants appeared, including magnolias and palms (~140 mya)
Cenozoic 65 to present

(Dates provided by the Geologic Time Scale from the Geological Society of America)

Evolution of Plants

Plant reproductive structures have changed significantly over time and are a good indicator of evolutionary progress. The first land plants, including horsetails and ferns, produced new plants via spores.  Gymnosperms were the next major group of plants to evolve. They produced true seeds in cone-like structures. After that came the angiosperms — plants with “true flowers” that produce seeds within protected ovaries (fruits). This innovation gave angiosperms an adaptive advantage over naked-seeded gymnosperms, and now they’re the most abundant type of plant on the earth.

Dino Plants for Your Garden

Here are descriptions of some plants with prehistoric origins that are still around today that you can bring in to help your students recreate a Mesozoic environment in your youth garden.

Spore-Bearing Vascular Plants

Spore-bearing vascular plants do not have seeds, but instead reproduce through spores in alternating generations. They can also propagate asexually from their underground stems.

Ferns were once the primary vegetation covering the earth! The ancient species were probably similar to the tree ferns, now found only in some tropical regions. These dominant plants of the dinosaur era decomposed to become a major component of coal deposits, an important energy source for us today.

The ability of ferns to adapt and evolve has resulted in more than 12,000 known living species growing in climates from the tundra to the tropics. Some of the earliest species include the maidenhair ferns (Adiantum species), lady ferns (Athyrium species), and autumn fern (Dryopteris erythrosora). Fern leaves, called fronds, grow from rhizomes (underground stem structures that grow just below the soil surface). Ferns range in size and shape from low mounding ground covers to the tree ferns mentioned above. Most ferns grow in woodlands and are well adapted to shady beds and indoor plantings.

The life cycle of ferns varies from the cycle of other common garden plants. Ferns reproduce from spores produced over two distinct generations. The part of the cycle we can easily observe is the development of the green fronds. On the undersides of delicate fern fronds, microscopic, dust-like spores are encased in structures called sporangia. Clusters of sporangia called sori are the scale-like bumps one can see on the underside of the fronds. When the sori turn brown (in natural settings, this is typically after midsummer), they are ripe and ready to release spores. Use a hand lens to look closely at sori —those that are ragged looking have probably already opened and released their spores.

The spores fall to the ground and sprout when temperature and moisture conditions are right. But instead of producing fronds, spores develop into small, green heart-shaped plants known as prothallia. This is the gametophyte generation because male and female reproductive organs form on the prothallia that produce gametes, akin to pollen and ovaries in seed-bearing plants, which combine with the help of moisture to form spores. It’s easy to miss this part cycle because prothallia are tiny and lie close to the ground. When spores are released, they grow into the familiar frond-bearing plant (the sporophyte generation).

Horsetails (Equisetum species) are among the oldest plants in existence. Like their close relatives, the ferns, horsetails reproduce via spores rather than seeds, and horsetail species are also adapted to grow around the globe. They grow in marshy areas and sport two different types of vertical, hollow stems. The first stems appear in the spring and look something like asparagus topped with brown cone-like structures that bear the spores. Later in the year larger stems with stringy, tough leaves emerge, and these give plants a feathery appearance (like a horse’s tail). If planted in a favorable location, horsetails spread quickly — in fact, they are considered invasive weeds in some areas. Check with local native plant organizations or your state’s conservation agency about the invasive status of horsetails in your region before planting them in your school landscape. If you do choose to plant them, consider planting in a container to keep them from spreading aggressively.

Another common name for horsetails is scouring rush. This gives away one if its important uses. Horsetails have very fibrous stems that contain silica crystals, making the stems an excellent material for cleaning pots and pans. Historically, people tied bunches of horsetail stems together to form homemade scouring pads for cleaning dishes. Furniture makers also used them to polish their wares. Even though steel wool and sandpaper have replaced them in most places, there are some cultures that still use horsetails for cleaning and polishing.


Gymnosperms produce true seeds in cone-like structures. The word gymnosperm means “naked seed,” ‘ pointing out the fact that the seeds aren’t covered with an ovary (fruit).

Bald Cypress (Taxodium distichum; USDA Zones 5-10) is a tree that can grow in both saturated and dry soils, making it a popular street tree. Bald cypress can reach 120 feet tall, and in wet areas develops distinctive “knees” (hump-shaped roots that grow out of the ground). Although many gymnosperms are evergreen, the bald cypress is deciduous and provides attractive fall color.

Bald cypress seeds are a food source for wildlife, including turkeys, wood ducks, and squirrels. Some have referred to the lumber as “wood eternal,” not because the species has been in existence for ages, but because the heartwood is resistant to decay and thus is used to make docks, boats, and bridges. Historically, the Choctaw used the bark for string and rope, and the Seminoles found bald cypress useful for making houses, canoes, and ceremonial objects.

Dawn Redwood (Metasequoia glyptostroboides; USDA Zones 4-8) is another deciduous tree first identified from fossils. Scientists thought it was extinct, but during World War II a grove of surviving trees was discovered in a remote location in China. Seeds were harvested and you can now find this attractive tree in landscapes throughout the world. Dawn redwood can reach heights of more than 120 feet, and it is useful for stabilizing soil in wet areas.

Gingko (Ginkgo biloba; USDA Zones 4-9) is another deciduous landscape tree with unique fan-shaped leaves known for beautiful fall color. Until it was “discovered” growing Japan by a 17th-century Dutch botanist, Europeans believed all ginkgo species were extinct. Male and female reproductive structures form on separate trees, and because the fleshy outer layer of seeds borne on female trees gives off a putrid odor, male trees are a better choice for landscapes. Despite the smell, the seeds are a delicacy in many Asian cultures. Extract from the leaves has become a popular herbal remedy purported to improve memory.

Cycads are gymnosperms that resemble palms. The cycad commonly called coontie (Zamia pumila), with its soft fern-like leaves, is a good candidate for a youth dinosaur garden. This mounding shrub reaches approximately three feet tall and sports evergreen foliage that grows well in either full sun or shade. It’s hardy only to Zone 8, but gardeners in cooler climates can grow it in a container and bring it inside during the winter. Although coontie seeds are poisonous, the Seminoles and early European settlers used the root as an ingredient to make bread. Sago (Cycas revoluta) is another ancient cycad popular for landscape use, but its sharp-edged leaves make it a less appealing choice than coontie for a youth garden.


Angiosperms are plants that produce seeds enclosed in an ovary (fruit). This is the major feature that sets them apart from gymnosperms. This evolved packaging can serve as protection for the seeds and also aid in distribution to help the plant spread to new locations.  Both of these features are enhancements because they are beneficial to overall survival of the species.

Magnolias (Magnolia species; USDA Zones 4-10) are some of the earliest angiosperms. There are more than 80 different species ranging in size from small shrubs to huge trees. Some, like the southern magnolia, are evergreen, and others, like the saucer magnolia, are deciduous. All are known for their beautiful and often fragrant flowers. Look for varieties that grow well in your area.

Palms are native to tropical and subtropical areas of the globe. Even today the fruits of many palm trees are used for food (think dates and coconuts). Two of the hardiest palms to consider for your dinosaur garden are the pindo palm and the windmill palm. The pindo palm (Butia capitata; USDA Zone 8-9) has a very graceful appearance with feathery leaves that curve down towards the trunk. It also produces a healthy crop of edible orange fruit that some people use to make jelly. The windmill palm (Trachycarpus fortunei) is among the most cold-tolerant palms (hardy in USDA Zones 7b-10, and known to survive winter snow) and is a common landscape plant.

Laying the Groundwork:

Ask students:

-Do all plants have flowers? Can you name a plant that does not have a flower? (If students list plants in the latter category that do have flowers, such as an oak tree, collect a sample, or use photographs to show the variations in flower shapes.)

– Do all plants have fruits? Can you name a plant that does not have a fruit?

– Do all plants have seeds? Can you name a plant that does not have seeds? (ferns, mosses)


  1. Introduce students to the common characteristics of ferns, gymnosperms and angiosperms as listed in the background information above. For quick reference:

Ferns reproduce from spores produced over two distinct generations. The sporophyte generation is the part of the cycle we can easily observe is the development of the green fronds. The gametophyte generation is when spores develop into small, green heart-shaped plants known as prothallia and form male and female reproductive organs that then form spores that produce the frond-bearing plants. Some common characteristics of ferns include

  • fern fronds which before opening are known as fiddleheads
  • sporangia located on the back of leaves
  • reproduce by spores rather than seeds
  • water is necessary for reproduction to occur

The word gymnosperm means “naked seed,” which refers to the fact that the seeds are produced in a cone structure rather than being enclosed in a flower/fruit like angiosperms. Some common characteristics of gymnosperms include:

  • needle- or scale-like leaves, frequently evergreen
  • no “true” flowers
  • seeds produced in cones
  • pollinated by wind

As always, there are exceptions to every rule. For instance, the gingko is a gymnosperm, but it is deciduous and has broad leaves.

Angiosperms produce their seeds in enclosed fruits. Common characteristics include:

  • broad leaves, often deciduous
  • seeds produced by flowers and enclosed by fruit
  • pollinated by insects

Exceptions exist here, too. Many trees and grasses, which are angiosperms, are pollinated by wind.

Provide samples of plant parts from ferns, gymnosperms and angiosperms and ask students to fill out the following plant comparison chart:

FernSamples Gymnosperm Samples Angiosperm Samples
Describe the leaves.
What are advantages to having this kind of leaf?
What are some disadvantages of this type of leaf?
Describe the location of the spores/seeds.
What are some advantages of this type of spore/seed for the plants survival?
What are some disadvantages of this type of spore/seed for the plants survival?

Making Connections:

Make a list of all of the plants that are considered economically important in our society (for food, shelter, clothing, etc.).  Ask students to research whether these plants are gymnosperms or angiosperms and also find out what they need to make new seeds (wind, water, pollinators, etc.).  Use this information to introduce the current issue of decrease in pollinator populations.  What could this mean for our society?  Are there are non-plant alternatives for these economically important products?

Branching Out:

  • Take a nature walk around your school or home. Look for angiosperm and gymnosperm plants along your way. Bring a guidebook if necessary to help confirm your identification. Create an inventory to discuss your findings.
  • Ferns are being studied for their ability to help clean both air and soil. Ask students to explore phytoremediation, the process of using plants to help clean up pollution. Have them bring in current event articles to share related to this topic.


Garden How-to: Botanical Classification — or What’s in a Name?

botanical classificationDownload: Botanical Classification

You may say “po-TAY-to” and I may say “po-TAH-to”, but someone else might call it Solanum tuberosum ‘Yukon Gold.’ What’s with all these different names? Plants can go under a variety of monikers and it’s helpful to understand where the various names come from and what they mean.

Let’s start with common names. Everybody is familiar with them, but unfortunately, not everyone is familiar with the same common name for the same plant. For example, calling a tree by the common name of “cedar” may refer to one of several very different kinds of trees. To add to the confusion, frequently the same plant has acquired more than one common name. Vinca minor may be called periwinkle or myrtle; obedient plant and false dragonhead both refer to the perennial Physostegia.

Using the two-part or binomial Latin name (also referred to as the scientific or botanical name) for a plant can help clear up the confusion, at least most of the time. Each specific type of plant has a unique, two (occasionally three) part name. Let’s go back to our potato of the first paragraph. Solanum is the genus name. The genus (the plural is genera) applies to a group of related species that share certain characteristics. So eggplants, which are related to potatoes, are also in the genus Solanum.

The second part of the Latin name is called the specific epithet and applies to the particular plant. So potatoes are Solanum tuberosum and eggplants are Solanum melongena. The two names together designate the plant species. On occasion there may be further divisions into subspecies, botanical variety or forma, making a three-part name.

Lots of people shy away from using Latin names because they are unsure how to pronounce them, and admittedly there are some doozies. Ostrich fern is lots easier than Matteuccia struthiopteris, no contest! But most aren’t that daunting if you simply sound them out. And gardeners have learned to easily use the many that double as common names — think of Delphinium, Iris, Sedum and Hosta.

But what about the ‘Yukon Gold’ in our potato example? This is the cultivar name, which follows the species name in single quotes. Cultivar refers to a “cultivated variety” of a species that has been deliberately selected by breeders for one or more specific, desirable characteristics that are retained when the plant is propagated in a way that will maintain those characteristics. Cultivars, which originate through selection by humans, are distinguished from naturally occurring botanical varieties. However, the general term “variety” is often loosely used when “cultivar” is the more accurate term. What all this means to a gardener is that all plants of a particular cultivar can be counted on to have the same unique set of characteristics. All ‘Yukon Gold’ potatoes will have yellow skin and flesh, whereas the cultivar ‘Caribe’ will produce white-fleshed potatoes with bluish-purple skins.

Sometimes you’ll see scientific plant names with the letter “x” between the genus and the specific epithet. This indicates that the plant is a hybrid, a plant that is the result of a cross between different species or cultivars. Some hybrids occur naturally, while others are the result of intentional crossing by plant breeders to produce plants with specific traits.

Especially with ornamental plants, you may see plants called by yet another name, usually one with lots of marketing appeal. For example, you may see a popular hydrangea on sale at a local garden center called Endless Summer®. But if you look at the fine print on the tag, you’ll see the name Hydrangea macrophylla ‘Bailmer’ (PP 15,298). The official cultivar name is ‘Bailmer,’ but the registered trademark name (denoted by the symbol®) is the more marketable Endless Summer, while the numbers following the name indicate that the plant is patented. This means that for the next 20 years, only the patent holder can commercially propagate and sell the plant or license the rights to do so. (You may also see the ™ symbol used; this signifies a trade name that has been claimed but not yet registered with United States Patent and Trademark Office.) Plant sellers sometimes confuse the trademark name with the cultivar name, writing it after the species name in single quotes. So it’s not uncommon to see the above hydrangea listed (incorrectly) as H. macrophylla ‘Endless Summer’. As a consumer, it’s mainly important just to realize that there may be a number of different ways of naming the same plant.

And finally, we said earlier that using Latin names for plants clears up uncertainty as to the actual identity of the plant most of the time. Unfortunately for gardeners who’ve learned their botanical Latin, plant taxonomists sometimes revise the long-used scientific names of plants for greater botanical accuracy—and, often, greater gardener confusion! For example, many plants previously found in the genus Aster have recently been moved to various new genera. An example is the smooth aster, formerly Aster laevis, now named Symphyotrichum laeve. (Why does the new name always seem to be harder to spell and pronounce than the older one?) Botanical name changes may make things tricky when you consult plant catalogs and other references; some get updated quickly, some continue to use the old names, so it helps to be aware of both. A rose by any other name may smell as sweet, but if you’re trying to find it in a catalog, it helps to know what it answers to!

Swiss Chard

Download: Swiss Chard Growing Guide

swiss chard growing guideFun Facts

  • How chard acquired the adjective Swiss in its name remains a mystery, since it has nothing to do with Switzerland! It is also referred to simply as chard. The name chard is reputed to have come from either the French word for cardoon, a different vegetable that resembles an artichoke plant, or from the Latin word cardus, for thistle.
  • To add to the confusion, chard has acquired a variety of other common names. In English, it’s been known variously as silverbeet, strawberry spinach, Roman kale, and leaf beet, among others.
  • Chard is a biennial plant, meaning it has a two year life cycle, but it is cultivated as an annual in the vegetable garden and harvested in its first season of growth. Once it begins to flower and set seed in its second year, its leaves turn bitter and unpalatable.
  • Both the leaves and stalks of chard are edible. Young leaves may be eaten raw in salads, while older leaves and stalks are generally served cooked.
  • Chard is an excellent source of Vitamins K, A and C.

Growing Guide

This beet relative and Mediterranean native has been cultivated for centuries. Chard provides plenty of nutrition and good taste, along with more heat tolerance than many kinds of greens, so it’s a popular choice for gardeners across the county. Some varieties of chard have colorful stems that contrast with its broad green leaves, making it a great choice for edible landscaping, where edible plants are combined with ornamental ones to add beauty and interest to the landscape instead of relegating them to a strictly utilitarian vegetable bed.


Cultivars of chard vary mainly by the color of the stems. Some varieties have white stems and leaf veins; some have bright red or yellow; and some come with stems in a mixture of hues, including gold, pink, red, orange, purple and white. Most have savoyed or crinkled leaves.


Full sun and fertile, well-drained soil will give the best results. In warm climates, light shade during the hottest part of the day is helpful in extending the spring harvest season.


Begin sowing seeds as early as 2 weeks before the average last frost date in spring. Chard seeds are usually sown directly in the garden, but for the earliest harvest plants can be started indoors 6-8 weeks before the last spring frost date, hardened off and set out 2 weeks before the last frost date. Except in the warmest areas, make succession plantings every few weeks up until about 2 months before your average fall frost date. In the warmest parts of the country, make early spring and late summer to fall sowings. Hardy chard plants will weather temperatures down to about 20°F.


Sow seeds about ½ inch deep and 4 inches apart. As with beets, chard “seeds” are actually dried fruit capsules containing multiple seeds. Seedlings sprout in clusters; so no matter how carefully you space out the seeds at planting time, you’ll still need to do some thinning. After seedlings produce their first set of true leaves (what appear to be the second set of leaves), use a pair of small, sharp scissors to snip out all but one in each cluster. Then when plants are 4-6 inches high, thin them again to stand 8-12 inches apart. (Use the tender leaves from this second thinning in a spring salad.)

Chard is also a good crop to grow in containers. A 5-gallon pot is a good size for three chard plants. Or combine chard with flowers and herbs in a half-barrel planter for a decorative and edible display.


For vigorous growth, feed chard plants with a high nitrogen fertilizer every 4-6 weeks. Make sure plants have a consistent supply of moisture throughout the growing season, especially when the weather turns warm.


Flea Beetles. These small, black beetles, which jump like fleas when disturbed, chew numerous small holes in leaves. Cover beds with row cover fabric as soon as seeds are planted to keep beetles away.

Leaf Miners. Adult flies lay eggs in leaves that hatch out into larvae that feed within the leaf tissue, creating visible winding tunnels. The best way to avoid damage is to cover beds with row cover fabric as soon as they are seeded to prevent egg-laying.

Leaf Spot. Cercospora leaf spot is a fungal disease that can infect chard, as well as beets and spinach, causing brown or gray spots with reddish margins. To help reduce problems with this disease, rotate the location of susceptible crops in the garden on a 2-year cycle; clean up plant debris well at the end of the season to get rid of infected residues; make sure to thin plants to ensure good air circulation; and keep leaves dry by using drip irrigation or watering plants overhead in early morning so leaves dry quickly.


You can begin harvesting plants when their leaves are about 6 inches long, usually about 6 weeks after planting. For an extended harvest, break or cut off the outer leaves at their base, leaving the plant’s inner leaves to continue growing. You can also let plants grow to their mature size (1-2 feet tall) and harvest the entire plant.

Find out how to make Swiss Chard, Kale and Feta Salad and other tasty chard recipes from Vermont Harvest of the Month.

Vegetable Scrap Painting

vegetable scrap painting

It’s been a looooong cold winter here in Vermont, and it’s only January. When it’s dangerously cold outside (high of -5°F) our family starts getting into science experiments and art projects. Trying to think of ways to brighten up our winter doldrums with a garden-related activity, my mind turned to the KidsGardening lesson plan Exploring Plant Dyes.

Not one to actually follow directions, I took some liberties with this lesson plan. First, I didn’t really want to permanently dye anything, but since we go through an obscene amount of paint in our house, I thought it might be interesting to try to make some paint from vegetable scraps.

As I was scrounging around in the refrigerator for the purple cabbage, I also found some rainbow carrots that had seen better days. My six-year old peeled a few outer leaves off the cabbage, and peeled the carrots. I chopped the carrots, and we put them in two saucepans with a few cups of water. We had one saucepan for the cabbage and dark purple carrots, and another for the yellow and red carrots. (Note, our purple carrots were purple all the way through. Some varieties have purple skin and orange flesh.)

After an hour or so on the stove, our purple veggie scraps yielded a lovely, deep purple water. The yellow and red carrots, though, barely colored the water at all. (We had been hoping for orange.) So I sprinkled in a bit of ground turmeric, and after 15 minutes or so, our water was very orange!

vegetable scrap paintingI strained the veggies out using a fine mesh strainer, and let the water cool in mason jar. I left it on the counter for a few days until we had some time to paint.

This was a mistake.

Guess what happens when you leave cabbage water in a tightly sealed jar at room temperature? Yep, it stinks. The turmeric paint wasn’t as bad.

As we’re painting, my six-year old says, “Mommy, this kind of smells bad. It smells like farts.”

The colors were muted, but it was still fun. If we did it again, which is a big if, I would plan to paint as soon as the water cooled.

The moral of this blog post? If you follow the directions in KidsGardening lesson plans or activities, you’ll likely have success. If you wing it, you end up with fart paint.

Five Tips for an Elementary School Cooking Program

school cooking program

As many of my loyal blog readers will remember (even though it’s been awhile), in my last post I wrote about my work with a formalized Food Science class offered at Burlington High School. This week I wanted to share a bit about how one of the elementary schools in our district has integrated cooking into their weekly schedule and their school culture. In particular, I wanted to share five of their strategies that I would consider best practices for starting a cooking program at your own school.

  1. Be intentional about what you grow in the school garden. Everything planted in the Champlain Elementary School garden is planted with a purpose. Vegetable varieties are often selected so that they can be used specifically in classroom cooking projects or by food service staff in school meals. Crops are strategically planted so that they reach full maturity in late summer and early fall, just in time for students returning to school. Before planting this coming season, put some thought into how your garden space could directly contribute to a handful of concrete cooking projects.
  2. Appeal to your community for donations. Local grocery stores have provided the school with grant money to acquire cooking supplies and gift certificates so that teachers can pick up ingredients for cooking projects. Teachers on the Outdoor Planning Committee have also leveraged relationships with district food service staff to assist with acquiring ingredients, though appeals to parents can yield just as productive results (for both foodstuffs and general supplies). Local kitchen stores can also be a good source of high quality donations or discounted items.
  3. If you can, have enough cooking implements for half your class. The key to Champlain’s culinary program is their mobile cooking cart equipped with enough cutting boards, box graters and whisks (just to name a few items) for an entire classroom. Having a large, well organized, collection of peelers, knives, measuring cups and spoons allows everyone to participate fully, though it’s not necessary for every single student to have their own rolling pin or spatula. In fact, when leading cooking activities I generally have students work in pairs and share tools; I find this promotes teamwork and cuts down on clutter and distractions.
  4. Have clear procedures that both teachers and volunteers understand. Cooking with a large group can be challenging and having an extra adult in the room can go a long way. Have clear standard operating procedures for cooking activities that both teachers and volunteers are trained on before they begin facilitating culinary projects. Have a written document that can easily be referenced or host a semi-annual training for both teachers and volunteers.
  5. Dedicate a set amount of time for cooking projects. Every Friday, at least four classes set aside an hour to participate in a cooking activity. While some teachers will pursue cooking with their classes on other days of the week, Fridays have become a set day where a volunteer or I will come in to help with these projects. Having a scheduled day each week where folks know they can jointly tackle a cooking activity with their students has created a sense of feasibility and sustained excitement for culinary projects, to the point that many would consider Cooking Cart Fridays an integral part of school culture.

Starting Seeds: What you need to know to be ready

 kids starting seeds

The winter solstice is past, and each day the sunlight coming in my windows is a little bit stronger and lasts a little bit longer. While the cold and snow outside tell me winter is still keeping a firm grip on my Vermont garden, these gradually lengthening days hold out the promise of spring weather ahead. They tell me that, in spite of snowstorms and below-zero nights, gardening season is on its way and it’s time to think about starting seeds indoors.

Although January is too early for me to actually begin planting seeds indoors in my climate, it’s a good time to start planning which seeds to start and ordering them online or purchasing packets at my local garden store. (For help figuring out what to start when in your climate, see When to Plant Seeds.) It’s also the time to check that all my seed-starting supplies are ready, from fluorescent grow lights to germinating mix to cleaned and sanitized pots recycled from previous seasons. (To get re-used containers ready, I scrub them in warm, soapy water; rinse them; then soak them in a tub filled with 9 parts water and 1 part household bleach for 15 minutes. Next I rinse them with clear water and let them air dry.)

All seeds are in a state of suspended animation, waiting for the right set of conditions to awaken and begin to sprout. For many kinds of seeds, warmth and moisture will rouse them into growth. But for some kinds of seeds, germination requirements are more complex. Some seeds contain chemical and physical inhibitors that keep them from germinating when the environment isn’t suitable. Once the seed receives the proper conditioning that destroys these inhibitors, it “knows” that it’s safe to start on the journey to becoming a plant. Understanding what conditioning particular seeds need sets you on the path to starting these seeds successfully.

Some seeds have a very hard seed coat that in nature is broken in a variety of ways that assure that the seed germinates under the proper conditions. Alternate freezing and thawing temperatures, extreme heat from a fire, passing through the digestive system of an animal are all ways in which a hard seed coat can be breached to allow moisture in. We can reproduce this conditioning with a procedure called scarification, which is simply nicking, scraping or cutting through the seed coat.  For example, you can cut off the pointed end of a morning glory seed with a sharp razor blade or scrape the seeds across a piece of sand paper. If you have a lot of seeds to scarify, put them in a jar with some coarse sand and shake vigorously.

Sometimes soaking is enough to soften the seed coat to speed germination.  Soaking can also speed germination by removing chemical inhibitors from the seed coat. Soak parsley seeds for 24 to 48 hours before planting, pouring off the water and replacing it with fresh several times, discarding the leached out inhibitors in the process.

When we think of planting seeds, what springs to mind is usually a picture of tucking seeds into the soil. And while some seeds do need the darkness of a soil covering for germination, most will germinate in light or dark, though the covering of soil helps to keep them moist.  But some do require exposure to light to break down inhibitors in the seed coat. Lobelia, impatiens, and ageratum are flower seeds that need light for germination; simply press them on to the surface of the germinating medium, rather than burying them.

Certain seeds, usually of perennials, trees, and shrubs from cold-winter climates, need to be exposed to a certain duration of cool temperatures before they’re ready to germinate. This chilling requirement prevents them from sprouting prematurely when the weather is too cold for growth. In nature, these conditions are provided by normal seasonal changes.  When gardeners mimic this process, it’s called stratification. Seeds are given a period of moist cold (40-45 degrees F) for about 6 weeks to duplicate going through a cold winter; a refrigerator easily provides the appropriate “winter” chill.

Once seeds have been conditioned, most need warmth in addition to moisture to germinate well. The majority of the seeds we start early indoors appreciate bottom heat from a seedling heat mat or the top the refrigerator that keeps the germinating mix between 70 to 80 degrees F.

How to know what’s best for sprouting various kinds of seeds? Check the instructions on the seed packet for the specific requirements of the seeds you’re starting. Happy planting!

Sweet Potatoes!

Sweet Potatoes

Download: Sweet Potato Growing Guide

sweet potatoesFUN FACTS

  • Although they are often referred to as yams, sweet potatoes are not actually yams. A true yam is an entirely different and botanically unrelated, edible tuber that is starchy, not sweet, with coarse, tough, almost bark-like brown skin. True yams are grown as a food crop mainly in tropical climates in Africa, Asia, and the Caribbean.
  • Sweet potatoes are North Carolina’s official state vegetable. This state is also the leading producer of sweet potatoes in the U.S.
  • George Washington Carver , working in the early part of the twentieth century, developed 118 different products from the sweet potato, including dyes, candies, molasses, wood filler and library paste!
  • The sweet potato was introduced to China towards the end of the sixteenth century, where it quickly became a staple crop. Because it grew well on land that was not suited to traditional Chinese crops, it helped to fuel a major population increase. Today China is the biggest producer of sweet potatoes in the world.


Despite their name, sweet potatoes are not related to Irish potatoes. In fact, they are members of the morning glory family! One of the most nutritious vegetables around, sweet potatoes are high in Vitamin A and C, potassium, antioxidants, fiber and complex carbohydrates. Sweet potatoes are warmth lovers and grow best in southern gardens. But with a little extra effort, even gardeners in many northern areas can reap a respectable harvest of these tasty, nutritious tuberous roots. And, unlike many common garden veggies that are grown from seed, sweet potatoes are grown from rooted cuttings, called slips.

Native to the tropical lowlands of Central America and parts of South America, where they have been cultivated for thousands of years, sweet potatoes were brought back to Europe by Christopher Columbus in the fifteenth century. Spanish and Portuguese explorers carried these nutritious tuberous roots with them around the globe, introducing them to the Philippines and eventually to China, where they became a dietary staple that helped to stave off famine, supported population growth and profoundly influenced the course of Chinese history.


Sweet potato cultivars fall into two main categories: those with moist flesh and those with dry flesh. Varieties with moist flesh are the most popular. They generally have bright orange or deep yellow, very sweet flesh and grow best in warmer climates, although there are a few varieties such as ‘Beauregard’ and ‘Georgia Jet’ that mature relatively quickly and do well in northern gardens.  Dry-fleshed varieties, with yellow, white or purple flesh, are starchier and not as sweet and also offer some varieties that do well in cooler climates.


Be sure soil in your sweet potato bed is well-drained.  Plants need full sun, although those grown in the warmest areas may tolerate a little afternoon shade.  Sweet potatoes are vining plants, so be sure there is plenty of space for the vines to run.


Sweet potatoes are started from rooted cuttings called slips that are planted in the garden when the soil is warm (at least 55°; 65° is best) and all danger of frost is past, usually a couple of weeks past the average last frost date.


Slips can be purchased from mail-order nurseries or local garden stores. Don’t be alarmed if slips look limp before planting time; they will revive once they’re in the ground.  You can also start your own slips if you have disease-free sweet potatoes stored from the previous growing season. Starting slips from supermarket sweet potatoes isn’t recommended as they are often treated to prevent sprouting, and you won’t know which variety you have and whether it’s suitable for your climate.

To produce homegrown slips, stick several toothpicks into the middle of a sweet potato and set it in a jar so that the toothpicks rest on the rim of the jar. Fill the jar with enough water to submerge the bottom half of the sweet potato. Place in a warm spot out of direct sun and change the water weekly. In a couple of weeks, green sprouts will emerge from the sweet potato.  When the sprouts are at least 6 inches long, twist or pull them off from the sweet potato. Place the sprouts in new container with enough water to cover their bottom ends. Roots will form in about 10 days. Once they have formed roots, the slips are ready to be planted.

Plant slips about 3-4 inches deep about a foot apart in rows spaced 3 feet apart. Sweet potatoes can also be grown in a large (20 gallon) container.

In northern gardens, it’s a good idea to raise the soil in the sweet potato bed into mounds or ridges, and then pre-warm the soil by covering it with black or infra-red transmitting plastic mulch two weeks before the last frost date. Lay some drip irrigation lines before putting the plastic down. Then you can cut slits in the plastic through which to plant the slips, leaving the plastic in place.  Cover newly planted slips with row cover fabric for several weeks to give some protection from cool night temperatures.


Keep sweet potato plants weeded and watered consistently, especially as they are getting established. Plants don’t need much added fertilizer if the soil was well prepared before planting time; too much nitrogen fertilizer results in lots of leaves, but few tubers.


Tunnels or holes in tubers Tunnels or holes in sweet potato tubers may be the work of one of several pests. Wireworms are golden-brown, shiny, segmented worms that are the larvae of click beetles. In southern areas, the white, worm-like larvae of the sweet potato weevil may tunnel through plants into the roots. Sweet potato flea beetle larvae chew shallow tunnels just under the surface of the tuber.

Trap wireworms by burying chunks of Irish potatoes in the ground, with a stick shoved into each chunk so that it protrudes above ground. Wireworms will be attracted to the potato chunks, which can then be pulled up and destroyed.  Rotate the location of sweet potatoes in the garden on a 3-year cycle and cultivate soil in the fall to expose wireworms to cold and predation.  To prevent weevil damage, start with certified weevil-free slips; rotate the location of sweet potatoes in the garden on a 3-year cycle; and mound soil around the base of the plants to discourage egg-laying. Flea beetle adults are small, black beetles that jump when disturbed. They chew small holes in leaves, but most of the damage to sweet potatoes is done by their white, worm-like soil-dwelling larvae. To minimize their feeding damage rotate crops, keep weeds down, clean up plant debris well at the end of the season, and look for resistant varieties. Cover plants as soon as they are set out with row covers to prevent adult flea beetles and sweet potato weevils from laying eggs.

Root knot nematodes Infestation by these small, worm-like soil dwellers causes stunted plants that don’t yield well, as well as cracks and internal black spots in tubers. To minimize problems, look for resistant varieties, rotate the location of plants in the garden, add lots of organic matter to the soil to encourage the soil organisms that keep nematodes in check, and till the soil in the fall a couple of times after harvest.

Blackened leaves Sweet potato plants are very sensitive to cool temperatures; even temperatures between 40-50°F will damage leaves. In northern growing areas, cover plants with row covers near the end of the season to protect from night-time lows and harvest plants before night temperatures dip below 50°F. If some leaves are blackened by cold, cut them off right away and harvest your tubers as soon as possible.


sweet potatoesSweet potato tubers will keep getting larger as long as the weather is warm enough; unlike Irish potatoes their tops will not start to die back naturally. Use the days to harvest for the variety you’re growing as a guide, but harvest while night temperatures are still in the 50s to avoid chilling injury. Cut back the top growth first; then dig tubers out carefully to avoid nicking or bruising them. Move them out of the sun to a warm, humid spot (minimum 70°F; ideal 80-85°F) to cure for 10-14 days.  Cured tubers will store better and taste sweeter. After curing, store tubers in a spot with temperatures in the 55°-60°F range.

Make New Houseplants with a Rooting Pot

Make New Houseplants with a Rooting Pot

Rooting PotDownload: Make New Houseplants with a Rooting Pot

Got the winter doldrums? Get growing! Mid to late winter is a great time for you and your kids to do some indoor plant propagating. As days begin to lengthen after the winter solstice, plants will be stimulated back into active growth. And making new plants from cuttings will let you scratch your itchy green thumbs when it’s still too cold for outdoor gardening. Houseplant cuttings usually root in just a few weeks, so eager young gardeners can see results in short order.  And if you end up with more plants than you have space for on your windowsills, they make delightful gifts for friends and family that are full of the promise of the coming spring.

Making plants from cuttings is a form of asexual propagation—one that doesn’t rely on pollination and seeds. It produces clones—new plants that are genetically identical to the parent plant from which the cuttings were taken. Taking a cutting involves removing a piece of a leaf, stem or root and placing it in a growing medium where it then develops the other parts that were left behind (i.e., a section of stem will produce roots; a root piece will produce a stem).

While cuttings of some plants will root easily when placed in a container of water, others will rot before making roots if you place them in water rather than in a rooting medium. And the roots formed in a rooting medium are more robust than those formed in water, making your chances of success greater when it’s time to move the rooted cutting to a pot filled with soil mix for growing on.

Propagation is Easy with a Rooting Pot

Making a special propagation pot for rooting houseplant cuttings in a potting medium is an easy, not-too-expensive project that is fun for all ages. As we’ve noted, while many cuttings will form roots in water, rooting them in moist vermiculite usually gives consistently better results. Even difficult-to-root plants respond well to this rooting medium, and cuttings started this way seem to make the transition to potting mix in much better condition.

For best results be sure to start with fresh vermiculite and new, clean pots. Reused pots can be a source of disease contamination unless they have been soaked in a bleach-and-water solution, scrubbed thoroughly, and rinsed carefully to remove all traces of bleach.

Here’s what you’ll need:

  • 6- or 7-inch-diameter plastic or glazed ceramic pot with drain holes
  • 2-1/2-inch clay pot
  • Vermiculite
  • Paper towels
  • Small cork or florist’s clay
  • Sharp scissors, hand pruners or pocket knife

Vermiculite is a natural product made from expanded mica. The mica is mined and then heated to a very high temperature. This causes moisture that is trapped in the layers of mica to expand, and it puffs out like popcorn. It is then graded as to size and sold for different purposes. Larger chunks are used for insulation. The smaller sizes are used in greenhouses as a soil amendment. Vermiculite is readily available in most garden centers, but you can substitute perlite if you already have some in the potting shed.

Line the bottom of the plastic pot with some paper toweling to prevent the vermiculite from dropping through the drain holes. Then pour in the vermiculite, almost to the top of the pot. Next, plug the bottom of the clay pot very tightly with a cork. If you can’t find a small cork, green florist’s clay will work just as well.

Push the plugged clay pot into the center of the vermiculite so that the pot sticks up just a bit above the vermiculite, then water the vermiculite thoroughly. Excess moisture will drip through the drain holes. (This might be a little messy, but of course, that just makes it all the more fun for kids!) Fill the clay pot with water, too. After this first time, all you’ll need to do is keep water in the clay pot in the center. Because clay is porous, it will allow water to seep through into the vermiculite. As the vermiculite loses moisture, it is instantly replaced, provided you remember to keep that center pot filled with water. The moist vermiculite makes an excellent rooting medium, with just the right balance of moisture and air for good root development.

Taking Different Types of Cuttings

Now that you have your propagation pot ready, it’s time to take your cuttings. Listed in the table below are plants that grow well from cuttings and should provide you with a good success rate, even under tough classroom conditions.

Plant Plant Part
Coleus Stem
Pothos Stem
Geranium Stem
African violet Leaf or stem
Jade plant Stem or leaf
English ivy Stem
Snake plant Leaf

Most houseplants grow in a branching pattern with leaves angling off from main stems. Find a growing point where there are young, new leaves, and make your cutting 3 or 4 inches back from that tip. Cut about 1/2 inch below a node — the area where the petiole (leaf stem) or leaf blade joins the main stem. The node is an area of actively dividing cells. (This is a task for adults when doing this activity with young children.)

Next, push the cutting into the moist vermiculite so the node is just below the surface. New roots will form at this point. This step is easy for even the youngest of children along with a little adult guidance. Sometimes you have to remove the lower leaves in order to put the node into vermiculite. Be sure to do this because leaves will rot if they’re buried.

Some plants, such as African violets, do not branch but instead have a thick central stalk with leaves arranged in a whorled or circular pattern around it. For plants with this habit of growth, you can simply remove a single, medium-sized leaf and petiole. Trim the petiole so it is only an inch long. Then poke the petiole into the vermiculite so there is contact between the underside of the leaf blade and the moist vermiculite. New plantlets will form at the base of the leaf blade.

Snake plant (Sansevieria) is another example of a non-branching plant. You can take several cuttings from one of these long leaves. Each section should be 3 or 4 inches long. Place them carefully to be sure you get the bottom of each cutting into the vermiculite. If they’re turned inside down, they won’t root. New plantlets will form at the base of the cutting.

Heated indoor air can be quite dry. To keep humidity high around your cuttings as they develop new roots, when your cuttings are in place in the propagation pot, loosely drape a clear plastic bag over the top of the pot, propped up so that it isn’t touching any of the cuttings (chopsticks or popsicle sticks work well to hold the bag up). Then place the pot near a window where it will get bright light but no direct sun.

Make sure to keep the clay pot in the center topped up with water—the perfect task for budding young gardeners. After several weeks, show children how to pull gently on the cuttings. If they feel some resistance, they’ll know the cuttings have rooted. Scoop them out of the vermiculite gently and transplant them into small containers filled with potting soil. That’s all there is to it!

How the Potato Changed World History

How the Potato Changed World History

Download: How the Potato Changed World History

It may be hard to believe, but the humble potato is a world-changing vegetable. Today you might think that French fries and potato chips are the potato’s major contributions. But in terms of plants that influenced the course of history — socially, politically, economically, and ecologically — few other crops can compare.

The Columbian Exchange

Potatoes were unknown to the world outside the high elevations of the Andes and part of what is now Chile before that truly world-changing event, the arrival of Columbus to the New World. The influx of Europeans and Africans to the Americas that followed his arrival set in motion a chain of events that changed the face of the entire world. And many of these changes related to plants, including potatoes, maize, tobacco, cacao and rubber trees, crops previously unknown to the rest of the world.

The story of how the world changed when the Americas were linked first with the Europe and then with China is the subject of a fascinating book aptly titled 1493: Uncovering the New World Columbus Created (Alfred Knopf, 2011). Author Charles Mann details the wide-ranging changes that happened all over the globe as a result of what is called the Columbian Exchange, the ecological and economic exchange of plants, people, minerals, insects, and diseases that underlay major global changes such as the development of the African slave trade, the rise of European power, and the demise of imperial China, and whose influence continues to this day. According to Mann, “To ecologists, the Columbian Exchange is arguably the most important event since the death of the dinosaurs.”

Potatoes and the Rise of the West

So how does the lowly potato fit into all of this? When Spanish explorers arrived in the Andes, they found the people there cultivating a wide range of potato varieties adapted to specific conditions of elevation and soil. Unlike grains, potatoes are much more productive on a given amount of ground, and also unlike grains, potatoes contain sufficient nutrients to serve by themselves as the basis of a reasonably healthful diet. Although the acceptance of potatoes in Europe was slow initially (it was the first food that Europeans grew from tubers, rather than seeds, and was regarded with suspicion, even denounced as “an incarnation of evil” since it was not mentioned in the Bible), once it became accepted, it played a huge role in ending the hunger and famines that had previously been routine in Europe, creating the political stability that allowed European nations to prosper. Says Mann, “The potato fueled the rise of the West.”

The Great Hunger

But potatoes were also at the heart of the Great Hunger, the 1845-1850 famine that ensued in the wake of the devastating arrival of potato blight in Europe in the mid- 19th century. This disease, another import from the Americas, is thought to have reached Europe in a load of guano, bird excrement that is mined for use as fertilizer. Found on Pacific Islands off the coast of South America, guano had been used by Andean peoples to fertilize their potato fields. Europeans imported this cultivation technique as well, the beginning of the use of high-intensity fertilizers to improve crop yields that helped to make the potato such a staple and support Europe’s rise in population.

However, unlike in the Andes, the potatoes grown in Europe had little genetic diversity – in fact, most of the Irish potato crop consisted of one especially productive variety.  This genetic uniformity set the stage for an epidemic of disastrous proportions, as the potato varieties grown showed no resistance to the blight, and entire fields were wiped out in a matter of days.  The suffering that ensued was horrific, especially in Ireland, which endured one of the deadliest famines in history in terms of the percentage of the population affected. More than one million Irish died, and around twice that number emigrated, many of them settling in the U.S.

Celebrate Diversity

Can plants still change world history? Could an important crop again fall prey to a disease or insect on such an epidemic scale? According to Rob Dunn, in his timely book Never Out of Season (Little, Brown and Company, 2017), many important crops face just such a possibility. Modern agricultural practices that rely on just a few widely grown varieties or clones have streamlined food production for many important crops, while decreasing their genetic diversity. At the same time, we have paid too little attention to preserving the natural diversity of the ecosystems where these crops initially evolved, places where wild relatives of crop plants offer genetic resources to work with. If a new insect or disease appears on the scene that threatens a crop, or factors such as global climate change alter growing conditions significantly, plant scientists need a diverse genetic palette to work with in their efforts to breed new varieties with the resilience to meet new threats or to find new means of pest and disease control. Unless the genetic diversity of heritage agricultural varieties, along with what Dunn calls “wild nature,” is preserved, there may be little for scientists to work with.

A couple of examples bring this home. In 1970, a new fungus disease called southern corn leaf blight devastated fields of corn across the country. At that time, about 85% of the corn plants grown in the U.S. were of the same type genetically, called Texas cytoplasmic male sterile. All plants of this type were highly susceptible to the new race of fungus that had evolved, causing catastrophic crop losses. Fortunately, there were still older varieties of corn that carried resistance genes available for farmers and breeders to return to in the years that followed.

This may not be the case for one of our favorite fruits—bananas. Until about 1950, most of the bananas grown for export were of one variety, called Gros Michel. This variety, while tasty and productive, had no resistance to Panama disease, a fungal disease that began attacking banana plantations around 1900. By 1950, the Gros Michel banana was essentially commercially extinct. It was replaced with a new variety called Cavendish, considered not as high quality a fruit but immune to Panama disease. Again, this single banana variety was planted almost exclusively and is the one you find today in your local supermarket. Recently, and ominously, a new fungus disease that attacks Cavendish bananas has arisen in Asia, spread to East Africa, and will most likely make its way eventually to the banana plantations of Central America.  Unfortunately, the widespread monoculture of Cavendish bananas has resulted in the loss of many other, more local banana varieties from which breeders could draw for resistance genes. Will there be another banana variety (or varieties) to fill the void if Cavendish disappears? It remains to be seen.

Taking Action

How can you and your student gardeners help in the movement to improve the genetic diversity of crops and preserve the important resources that “wild nature” offers?

  • You can “think globally and act locally” by choosing to grow genetically diverse crops from heritage seed varieties in your school garden. Purchasing these seeds supports the seed growers who are working to keep varieties with broad genetic attributes commercially viable. Make sure your students understand that reasons for including heritage seeds in their garden.
  • Join and participate in a seed conservation organization, such as Seed Savers Exchange, whose mission is to promote a diverse “food crop heritage for future generations by collecting, growing, and sharing heirloom seeds and plants.” A great option for students is to participate in their Citizen Science Corps, helping to evaluate varieties by growing them in their school garden and reporting back on attributes such as vigor, yield, and eating quality. Native Seeds/SEARCH is a regional organization, helping to conserve crops adapted to the Southwest.
  • Buy locally grown foods produced using heritage seeds or plants. Encourage your local market to carry these diverse kinds and varieties of fruits and vegetables.
  • Support organizations that work to conserve important centers of crop diversity internationally. Check out this list of twenty seed saving initiatives preserving biodiversity around the world complied by Food Tank, a global community pushing for food system change.

Indoor Greening

Indoor Greening

Indoor greeningDownload: Indoor Greening

Overview: Create a green haven indoors by decorating your classroom and home environment with plants.

Grade Level/Range: Adaptable for all ages

Objective: Students will explore the benefits of indoor plants by designing (and creating, if resources allow) an indoor garden to enjoy during winter months.

Time: 1-2 hours to design, 1-2 hours to build


  • Indoor gardening books or Internet access
  • Paper and pencils
  • An old cart, wagon or wheelbarrow (optional)
  • Soil, pots and indoor plants (optional)

Background Information

As cold weather takes hold across the country, the predominant green of the landscape is replaced by browns, grays and whites. An important part of nature’s cycle, winter is a time for plants in most parts of the country to rest up for the spring show. Even though we know change is right around the corner, sometimes the short days and gray skies can be a real downer. Many gardeners combat this time by pouring over seed catalogs and dreaming of next year’s garden. An alternative is to create a green haven indoors by decorating your classroom and home environment with plants.

Historical Perspective of Greening the Indoors

Imagine the winter season without the modern-day conveniences of electricity and indoor plumbing. People relied on candles and fireplaces for light during gray, short days. Since water was pumped from wells and had to be boiled to be heated, baths were few and far between. Deodorants and perfumes were limited. Ask students to imagine what life would have been like when cold weather hit and folks became stuck inside small houses and buildings for long periods of time? How do you think they reminded themselves of the beauty of spring and summer to bring joy to the winter days?

People turned to evergreen plants for relief. Ancient Greeks and Romans would decorate their houses with boughs and wreaths of evergreens like holly as a way to symbolize nature and the promise of spring to come. The practice became part of a winter festival called Saturnalia honoring Saturn, the god of agriculture. The tradition continued through the years, although over time it became associated with the Christmas holiday. Starting in Germany during the 1500’s, whole evergreen trees would be placed indoors as symbols of protection and immortality.

Regardless of the symbolism attached to their placement, there was a more practical side to greening. The evergreen swags brought life into dull winter households. Decorative items like paintings and mirrors were rare and expensive, but greens were provided by nature for free for everyone’s delight. The greens also added a fresh fragrance to stuffy air. A precursor to scented candles and air fresheners, greens such as rosemary would be placed on the floor so that the room would fill with a pleasant aroma with every step.

Although modern conveniences have certainly lessened the unpleasantness associated with winter months, we can continue the tradition of greening our indoor environments today to enhance our quality of life. 

Decorating with Plants

Decorating with plants is a great way to continue the gardening experience in your classroom or at home through winter months. There are two main categories of greens, cut and potted plants.

Cut plants are those that have been detached from their roots such as evergreen branches. Some deciduous branches like forsythia and pussy willows are also fun to bring in, as the move to the indoor climate will force spring buds to open early. Although cut plant parts can be placed in water to extend their freshness, as soon as they are brought indoors the clock begins ticking down on their usefulness. As they dry, they will begin to loose their leaves and needles, along with their pleasant aroma.

Potted plants, however, still have their living roots intact in mini soil environments enclosed by a container. They continueto draw up nutrients and water and thus will provide green benefits longer. A challenge with potted plants is finding varieties that will thrive with the indoor conditions of lower light. During much of history, potted plants were reserved for the very rich who could afford to build glass houses or conservatories to grow plants indoors. However, the discovery and propagation of tropical plants growing in low light rainforest conditions, the invention of electricity and thus increased artificial light available in indoor environments and the addition of more windows to building structures have made potted plants an affordable option for all.

Benefits of Bringing Plants Indoors

There are many benefits to adding plants to your indoor environments including:

Brighten the décor and create a nurturing environment.

Whether we recognize it or not, humans respond positively to green. Being surrounded by the green of nature helps to relax us, inspires peaceful thoughts and decreases feelings of stress. Studies have also shown that plants can help in the healing process, with faster recovery rates for patients who have natural views. Check out these research findings:

People are more relaxed when viewing green landscapes vs. an urban scene. (Ulrich, R.S., and R.F. Simons. 1986. Recovery from stress during exposure to everyday outdoor environments. p. 115-122. In: J. Wineman, R. Barnes, and C.Zimring (eds.). The Costs of Not Knowing. Proceedings of 17th Annual Conference of the Environmental Research and Design Association, Washington, D.C.).

The presence of plants in a room increases attention and reduces stress. (Lohr, V.I., C.H. Peason-Mims, and G.K. Goodwin. 1996. Interior plants may improve worker productivity and reduce stress in a windowless environment. Journal of Environmental Horticulture. 14:97-100.).

Students perform better when the view from their room is dominated by plants vs. buildings and pavement. (Tennessen, C.M., and B. Cimprich. 1995. Views to nature: Effects on attention. Journal of Environmental Psychology. 15:77-85.).

Patients in hospitals recover more quickly and experience less pain if their rooms look out onto trees rather than on a building. (Ulrich, R.S. 1984. View through a window may influence recovery from surgery. Science 224:420-421.).

Clean the air.

Plants clean the air around you. It’s not just that plants absorb the carbon dioxide we exhale and give us fresh air to breathe in return; they’re also extremely effective at removing environmental toxins, like formaldehyde and benzene, from the atmosphere.

The ability of houseplants to clean the air has been recognized for decades. How do they do it? As part of their normal life processes, plants draw air in through their leaves. The plants themselves break down some pollutants during their normal physiological processes, but soil-dwelling microbes around plant roots do much of the work, too.

It’s not just what they absorb that make plants great companions, it’s also what they give off. Plants transpire water vapor, making them natural room humidifiers, and even though they grow in soil, they can reduce the amount of interior dust by up to 20 percent, according to research from Virginia Tech. Dr. B.C. Wolverton discovered that they emit substances that suppress airborne bacteria and mold spores, reducing these hazards by 50 to 60 percent.

In the 1970’s and ‘80s, NASA research aimed at designing a livable moon base using plants to clean the air yielded results that are applicable right here at home. Some of the best living air purifiers are areca palm (Chrysalidocarpus lutescens), English ivy (Hedera helix), rubber plant (Ficus robusta), Boston fern (Nephrolepis exaltata), schefflera (Brassaia actinophylla) and bamboo palm (Chamaedorea sefritzii).

Basic Indoor Plant Care

The benefits of plants in the indoor environment are significant, but it is important to recognize that unlike other decorative materials, they are not maintenance free.

To care for cut plants:

Many cut plants can be placed in water to extend their life. Stems should be re-cut immediately before placing in the water because sap may gather at the base and block new water uptake. Additionally, the water should be refreshed periodically to avoid bacteria build up which can generate unpleasant odors. Their life can be extended by keeping them out of direct sunlight and away from heaters and/or drafts which may speed up the dehydration process.

To care for potted plants:

Potted plants will require the following care:

Watering – Since (hopefully) rain is not falling inside your home or classroom, you will need to provide water for your potted plant. Try to avoid both over-watering, which can lead to root rot, mold and fungus gnats, and under-watering, which can lead to stunted plant growth and leaf drop. As a general rule, let your plant dry out to the point that the top inch or two (depending of the size of your container) of soil feels dry to the touch, then water your plant until it begins to drain from the bottom of the pot. Remove any excess water from the plant tray so that the pot does not sit in water. How often will you need to water? Water needs will vary greatly with indoor conditions including temperature, light and humidity, so it’s best to check your plant frequently and water as needed rather than trying to stick to a specific watering schedule.

Fertilizing– Using potting soil with added fertilizer will provide the nutrients your plants will need for healthy growth for a few months. However, with time or if your potting soil does not contain any fertilizer, you will need to supply nutrients through either an organic or chemical fertilizer. Worm castings and tea from an indoor compost bin are a great source of nutrients for classroom plants. Most indoor plants have very low nutrient needs and will provide you with signs such as yellowing leaves or slow growth if fertilizer is needed.

Lighting – Sunlight from windows provides an adequate source of light for many indoor plants. However, if you begin to notice tall, lanky growth or yellowing of leaves, your plants may not be receiving enough light for proper growth. You can supplement with artificial lighting in a setting like a GrowLab.

Repotting – Making sure you have the right size pot is critical for maintaining proper moisture levels. Too small of a pot can lead to root circling and the need for frequent watering; however containers that are too large makes it very easy to over water. A good general rule is to go up only one or two pot sizes when repotting.

Click here for more information about indoor gardening.

Laying the Groundwork:

Ask students to describe how the outdoor winter landscape looks different than it does the rest of the year? How does this make them feel? Do they miss the green of their garden and landscape plants?

Come up with a list of places where they have seen indoor plants. How do those spaces make them feel? Share the information about the benefits of indoor plants from the Background Information.


  1. Tell students you are going to challenge them to design an indoor garden. Explain that indoor plants have the same needs as outdoor plants, including light, water, nutrients, air and space to grow. Fortunately for us, there are some plants that thrive in lower light conditions that can be delivered through sunny windows and indoor grow lights. The garden they design must be able to provide for all of their plants’ needs.
  2. Have students research different indoor growing systems, including windowsill gardens, light gardens and conservatories. Next explore your school building to see if you can find a good spot to plan your own indoor garden. Share the You Tube video about creating a mobile Indoor Fresh Air Garden from one of the 2017 Carton 2 Garden winners Jefferson Elementary School.
  3. Have students work in pairs or teams to design an indoor garden for your school. It can be a mobile or stationary garden, depending on your site availability. Some ideas for a stationary garden might include a shelving unit or even a hanging garden (see this idea from another Carton 2 Garden winner on how to build a hanging garden from old lunch trays). A mobile garden could be made from an old cart, wheelbarrow or wagon.
  4. After they plan the garden structure, have students research different plants that they think would grow well in their garden. Here is a list of a few possibilities to help them get started:

Plants to Try

The variety of indoor potted plants readily available at garden centers grows each year. In a classroom setting you want to stick to plants that are easy to care for and thus offer a high rate of success. Additionally, you may want to look for plants that propagate well to use for science experiments and for growing new plants for your young gardeners to take home. Depending on the age of your students, you may also want to avoid plants with poisonous parts. A comprehensive list of poisonous plants is available from NC State at:

On our list you will find an asterisk beside any plant listed in this database, even though most are only dangerous if consumed in large quantities or because they cause skin irritation in some people. Please visit the site for more details. Here are a few ideas for plants to try: 

Foliage Plants

Coleus*- A popular outdoor bedding plant, many varieties of coleus are adapted to shade and therefore can also adapt to indoor environments for the winter. They come in a wide variety of colors, sizes and shapes and can add a real punch of color to any room. Shorter varieties adapted to lower light levels do best indoors. Coleus plants are very easy to propagate from cuttings and can be started in both water and soil, making them an excellent stock plant for science experiments.

English Ivy* – An easy-to-grow evergreen vine with low light requirements, English ivy adapts well to indoor growing environments. It can be used to make topiaries that add a bit of whimsy to your indoor garden. You can purchase wire frames over which to train vines or you can make your own from coat hangers.

Ficus* – Also know as weeping figs or rubber trees, depending on the species, ficus trees are commonly grown indoor plants. They can be grown in a shrub-like, multi-trunk shape, or pruned to take on a traditional tree form. Their shape and size provides taller greening in a classroom. Another cool thing about ficus trees is that they can be propagated using air layering, where roots are developed without detaching cuttings from the mother plant. Air layering can be a challenging and intriguing experiment for older, more advanced students.

Ferns- There are a number of different types of ferns available for indoor gardens. Probably one of the most common is the Boston fern. Ferns grow well in hanging baskets and can work well in a classroom with limited shelf space. They prefer environments with higher humidity. Ferns have a very unique reproductive cycles producing spores rather seeds providing an opportunity to learn about the diversity of the plant kingdom in a hands-on way.

Jade plant – With thick, fleshy leaves that can store water when available, jade plants are very tolerant of infrequent watering and need little care. They also are excellent for propagation experiments and can be grown from both stem and leaf cuttings.

Polka-Dot Plant – This plant is as cute as its name, with bright splashes of speckled pink and green leaves. Although it can grow to a medium sized plant of 2 to 3 feet, it tends to stay much smaller indoors and does well in terrariums.

Pothos*- One of the easiest and least demanding indoor plants, pothos vines are vigorous growers. They can be grown in a regular pot and pruned to maintain a mounding appearance. Another option is to plant them in hanging baskets to allow the vines to cascade down. Alternatively, roots will form along the vines, allowing them to be grown up commercial or homemade moss poles or up a trellis to take advantage of vertical space. Their heart-shaped leaves may be solid green or variegated in green and white or green and yellow patterns. Pothos is very easy to propagate from stem cuttings.

Spider Plant – Widely available in variegated varieties with green and white leaves, spider plants can really brighten up a dull room. They can be grown in hanging baskets to save shelf space or grown in traditional pots. They produce lots of new plantlets on runners that can be used to start new plants. In humid environments, the plantlets will even form new roots while still attached to the stock plant. Spider plants are great to have on hand if propagating plants for plant sales or special projects.

Strawberry Begonia – A small, mounding plant that can be grown in a regular pot or a hanging basket, strawberry begonias also produce small plantlets on runners, which can then be separated from the mother plant to start new plants. Watching these “babies” grow is fun for kids and a great way to produce large quantities of new plants so each child can take one home.

Blooming Plants

African Violets – With sufficient light and regular fertilization, African violets provide attractive flowers when grown in indoor environments. The blooms are available in a rainbow of colors, but are most frequently found in shades of white, pink and purple. They can be propagated by both leaf and stem cuttings, and also when healthy, they will start to multiply in their pot and can then be propagated by division.

Begonias **- A wide variety of begonias are available, representing a diversity of leaf and flower colors. An interesting science topic to examine, begonias are monoecious, meaning they have separate male and female flowers located on the same plant. Their succulent leaves and stems make them great stock plants for stem propagation.

Phalaenopsis Orchids – Although often thought of us tricky to care for, phalaenopsis orchids actually require very little maintenance and do well in low light. Orchids are grown in a loose mix of bark and peat rather than traditional potting soil and prefer humid environments. They only bloom once a year, but the blooms can last for up to 3 months. From an education standpoint, the fused parts of the orchid flower can help you demonstrate the adaptations of flowers over time. 


Although many herbs prefer full sun, below is a list of herbs that you can try growing indoors under lower light levels. It is best to grow dwarf varieties and provide as much light as possible by placing in a south or west facing window or under grow lights.

Basil– Like other culinary herbs, basil is a stimulating sensory plant for children to smell and taste. Aside from traditional basil, there are also lemon, lime, anise, and cinnamon flavored types. Leaf color and shape also varies, from tiny, pale green leaves to deep purple ruffles.

Chives – Chives are normally grown for their flavorful leaves, which can bring a mild onion/garlic-like flavor to dishes like salads and baked potatoes.

Oregano- Oregano is a compact herb plant. The herb is a favorite in Greek, Italian, and Mexican cooking.

Parsley – Parsley is high in Vitamin A and by weight has more Vitamin C than an orange! The curly variety has a tight, mounding growth that resembles a bed of soft moss, making it a nice “touch plant.”

Thyme – Thyme is a small growing, woody shrub with oval leaves. Creeping varieties are a good fit for indoor growing.

*This plant is found on the Poisonous Plant List from NC State at: Please visit the site for more details.

** Wax and tuberous begonias are found on the Poisonous Plant List from NC State.

  1. Provide time for students to present their garden designs as a proposal to other classrooms, your principal and parents. Perhaps these supporters can help you find the funding to turn your garden into a reality.
  2. If possible, plant and care for your garden. Enjoy!

Making Connections

The ability to grow plants indoors is key for the future of space travel. Learn more in the lesson Plants in Space.

Create a survey and interview friends and family members to gather their thoughts and feelings related to indoor plants and greening. Compile and analyze your results.

Branching Out 

History – Learn about the history of orangeries, dedicated spaces in the homes and palaces of the wealthy used to grow tropical fruits. Find pictures of modern day conservatories or if possible, visit one in your area. 

Math – Develop a business plan to create an indoor gardening business. Business ideas might include growing and selling your own indoor plants or providing an indoor plant care service (many malls and office buildings hire people specifically to take care of their indoor plants, for example).

English – Create an indoor plant care brochure to share with friends, family and other community members.