The seeds of plants are dispersed to new locations in several ways. Birds, deer and other wildlife eat the fruits of many plants, later depositing undigested seeds onto soil miles away from the parent plant. Winged seeds of maple trees and the feathery seeds of dandelions travel long distances on the wind. Coconuts float from island to island. Some seeds hitch a ride on the backs of animals, stuck to fur or feathers, and even humans move seeds around, as this activity will show.

This activity is designed for small groups of children ages 6 to 12, either at home or in the classroom. The variety and quantity of collected seeds will vary with the season of the year.

Materials

Plastic seed germination tray (one per child), available from local garden centers

Sterile potting soil to fill trays

Blunt knives or screwdrivers

Spray bottle or watering can

Plastic wrap

Plastic bag (one per child)

Plastic pot labels

Permanent markers

The Activity

Take a walk! But before you start, have each child fill a germination tray with potting soil, leaving a half-inch of head space to hold the soil collected on the walk. Potting soil is often too dry as it comes from the bag and should be mixed with a small quantity of water before filling the tray. The moistened soil should be damp to the touch but not release water when squeezed. After filling the tray with moist soil, gently water the soil to settle it.

If possible, choose a place to walk that has a variety of habitats such as an open field crossed by hedgerows and surrounded by woods. Ask each child to walk through only one of the habitats. Have everyone wear shoes with deep tread, athletic shoes or winter boots, so that soil and seeds get trapped in the treads.

After walking through the assigned area, each child should use a knife or screwdriver to scrape the soil from the soles of the walking shoes into a plastic bag. Enclose a pot label marked with the student’s name and assigned habitat.

Back at the classroom or home, help each student spread the contents of the plastic bag evenly over the surface of the moist potting soil. Place the pot label in the soil at one corner of the tray. Gently spray or water the added soil, cover the tray with a layer of plastic wrap, and place it in a sunny window.

During the next two weeks, provide time for the students to check their trays regularly, keeping the soil moist. Ask them to keep a record of the number of seeds that sprout and the number of different types of seedlings that they observe. Which habitat produced the greatest number of seedlings? Which had the greatest variety of seedlings?

End this activity by discussing current worldwide concern over the human dispersal of weed seeds. Seeds can be transported around the world on the soles of travelers’ shoes. Many countries are inspecting the shoes of arriving airline passengers, removing foreign soil to prevent introduction of a weed.