Since fall is when many wild plants release their seeds, it's a good time to explore wild plants' seed dispersal strategies, collect them for you classroom garden, and experiment with methods of inducing them to grow. You'll have the best chance of success if you harvest seeds when they're ripe. Most of the wild plant seeds you collect will be mature or ripe 4 to 6 weeks after they've flowered. Have your eagle-eyed scientists carefully observe flowers in your area, looking for a change in fruit color from green to brown or black and a sign that the typically dark, firm, and dry seeds are ready to disperse.
Never collect seeds of any plant that seems to be in short supply in a given area ore that you know to be endangered. Leave plenty of seeds so that the plant can continue to produce new generations. If you're not planting seeds right away, dry them in an area with good circulation for a couple of weeks and store them in an airtight container in a refrigerator or other cool, dry place.
Although they're billed as hardy survivors, wildflower seeds can be challenge to germinate in your seemingly cozy classroom setting. Most wildflowers from cold climates require a dormant period of cold winter-like temperatures followed by spring-like warmth to germinate. This adaptation prevents them from germinating in the fall when subsequent winter conditions would prevent their surviving.
Your students may want to experiment with some of the following seed treatments to encourage seeds from wild plants to germinate in the classroom:
Scarring. Some seeds with hard coats will germinate more successfully if you use a file a sandpaper to scar the seed coat, taking care not to go deeply enough to injure the embryo. Invite your students to examine why scarring aids germination by looking at a bean seed and noticing the tiny opening near the scar where it was attached to the pod. This is the micropyle through which water enters. Try painting over the micropyle on one seed with nail polish, leaving one seed alone, and scarring a third seed. Soak them all in water, make predictions about how they'll look in a day, then compare them.
Soaking in hot water. Some seeds with hard coats, such as lupines, do best when placed in boiling water and then left to soak in the cooling water overnight before planting.
Moist chilling or stratification. Many seeds dispersed in the fall have internal dormancy, requiring a period of cold before they'll germinate. Consider putting seeds in a bit of damp peat moss, vermiculite, sand or potting mix in a plastic back or jar. Keep them in the refrigerator for 2 to 3 months before removing and planting.
You don't need a large area to start a wildflower patch near your school. Consider starting small, perhaps around the flagpole or in a 6-foot strip near the school. Contact a local Cooperative Extension office, soil conservation service, nursery or garden center for help assessing your site, planning, and identifying and finding seeds for plants that would grow best in your area.
Have students take an inventory of the proposed wildflower area. What plants are already there? Are there any native plants or wildflowers you'd like to leave? What are the light and soil conditions? Find out which plants would grow best in your area. If you decide to plant a range of single species as opposed to a wildflower mixture, have students consider heights, colors, and bloom periods, and design a map to scale on graph paper. If you choose to plant a mixture, make sure all the flowers are appropriate to your region. Don't be surprised if not everything comes up the first year. Annual flowers will predominate the first year, followed in subsequent years by increasing numbers of perennials and, if poorly weeded, a succession of grasses and other weeds.
Wildflower meadows should typically be planted from seed during cool, wet fall conditions. Some plants will germinate right away and establish a root system before overwintering. Others requiring winter-like temperatures will germinate with spring warmth and rains. If you don't plant in the fall, you can sow seeds outdoors in the spring when you'll also be transplanting any wildflowers started in the classroom. (Seeds that need chilling should emerge the second year.)
* If possible, plant wildflower seed outdoors in the fall.
* Choose a wildflower mix or individual species appropriate for your area.
* Loosen soil and clear out weeds before planting.
* Scatter wildflower seeds according to the seeding rate on the package and rake them lightly. They should have good soil contact, but should not be buried deeply. You can mix them with sand for better distribution.
* Don't fertilize. (Most wildflowers are adapted to poor soils)
* Don't expect everything to come up the first year.
The following are a few wildflowers that are relatively easy to start from seed indoors and to transplant outdoors in the spring. Most should germinate in 2 or 3 weeks in a worm classroom. Although native to particular areas of the country, these plants can be grown successfully in most regions.
Common Name------------Latin Name---------------------------------------------Planting Tips
Tickseed-----------------------Coreopsis lanceolata (perennial)---------Sow seeds on surface (They need light)
Black-Eyed Susan---------Rudbeckia hirta (perennial------------------Sow seeds 1/4" to 1/2" deep. (can stratify)
Indian Blanket---------------Gaillardia pulchella (annual)----------------Sow seeds 1/8" to 1/4" deep
Columbine--------------------Aquilegia canadensis (perennial)---------Sow seeds on surface (They need light.) Stratify for 4 weeks. May not bloom until second year.
Purple Coneflower--------Echinacea purpurea (perennial)-----------Sow seeds 1/4" deep. Try putting dry seeds in a plastic bag in the refrigerator for 3 to 4 weeks before sowing.
Is another's wildflower. A wildflower project can help your students discover that certain terms are relative and defined by circumstances. A weed, for example, is often defined as a plant that grows where you don't want it. But while black-eyed Susans may be a weed in my garden, they may be a star in your wildflower meadow. Typically, wildflowers are considered flowering plants, native to a particular region, that grow without intentional cultivation by humans. Many common wildflowers, however, were not native plants, but introduced intentionally or unintentionally from another area (e.g., Europe and now exist successfully in the wild-some so successfully that they are considered invasive weeds. Plants grown as wildflowers in one area will not necessarily grow wild in another area. As you students explore wildflowers, have them consider in which contexts each flower might be considered a weed, wildflower, or native plant.
Article published on June 23, 2008.