This project requires little more than several toothpicks, a carrot, and a plastic cup full of water for each student. Use toothpicks to partially suspend the carrots into the cup of water and place it in a sunny area. Have the students monitor and chart the growth of the carrots over time. As an interesting variant, have some students add small amounts of ingredients such as vinegar or salt to the water to see how these affect growth.
This project requires a square piece of sponge, several beans or sprout seeds, and a square plastic sandwich container for each student. Cut the sponge to fit snugly into the container, wet it and sprinkle seeds over the top. Make sure the sponges are soaked daily so that they stay moist. Monitor and chart the vertical growth of sprouts as well as the plant and root density over time. Measure plant and root density by counting leaves and main root stems that contain "fuzzy" growth.
This project requires a pickle jar, Styrofoam cut to fit the opening of the jar, vegetable sprouts, liquid plant food, water, crafting putty and a fish tank aerator. Punch holes into the foam so sprouts roots can be submerged in the jar while the plant shafts remain outside it. Suspend the plants by their shafts by adhering a tiny spot of putty against the Styrofoam cover. Set the aerator to a very low bubble to gently bathe the roots in oxygen.
This project uses plant gel (a nontoxic gelatinlike substance) as a suspension medium, eliminating the need for complex aeration systems for more demanding plants, such as herbs and vegetables. Sprout or seeds will grow in the plant gel as long as the water contains nutrients. Prepare multiple, separated growing cells (in an egg carton or segmented craft box) and supply them with different amounts of light. Cover the cells with tinted plastics that limit the intensity and wavelengths of light reaching them and measure how the different cells minimize or enhance growth.