For this project, quick-growing seeds work best. Preschoolers are not known for their patience. The more they can see the changes in their plant, the longer they are interested. If you want to plant vegetable seeds, pea, radish and squash are good choices. For flowers, choose petunia or zinnia seeds.
You can have each child be responsible to bring their own container from home. An easy alternative is to cut milk cartons or 2-liter bottles in half. The teacher should prepare the milk cartons or 2-liter bottles ahead of time, the children are too small to cut these materials themselves.
Place your containers in a space where they can get a minimum of 6 hours of indirect sunlight per day. You will also want to keep in mind how far away from the watering source that you place your seedlings. You do not want to have to carry the water too far.
Help each child place a few rocks or pebbles in the bottom of their planting container. Add some potting soil, then the seeds. Completely cover the seeds with the amount of soil recommended on the seed packet. Sprinkle with water. Observe the seedlings as the sprout into plants.
After the seedlings sprout, send the containers home with the children with instructions on how to transfer the plant. You can transfer the plants into larger containers or into a garden or flowerbed.