For this experiment, you need seeds or bulbs that will sprout fairly quickly. For seeds, try radishes. Place some radish seeds in a pot then watch how quickly they grows with proper care. Your child or student will also be excited to know that he will be able to eat the vegetables that grow on the plant. For a bulb, try a hyacinth. Place the bulb on top of a glass with a narrow opening. Fill the glass with water until it almost reaches the bulb. The bulb will soon start to grow roots and the plant will begin to come out the top. Transfer the bulb to soil and your child will have a bright colored flower.
Buy three plants that are potted and have already grown. The plants should be the same, such as three bleeding hearts or three mini orange trees in the same type of soil. Place the plants in the same area in the same amount of sunlight. Deny one plant water completely. Water another one as you are supposed to and give too much water to the last plant. Watch the effects the different amounts of water will have on the plants.
The sunlight experiment is similar to the water experiment. Buy three already grown, potted plants that are the same kind. Place the pots in different areas in your home. Put one plant in a sunroom or a window sill that receives a lot of sun. Place another plant in a window sill that receives shade for at least half of the day. Place the third plant out of direct sunlight, such as on a table away from a window. Watch how the amount of sunlight affects each plant.
Place some stones in a pot and spray the stones with water. Do not immerse them with water or making them soaking wet. Now, sprinkle seeds over the moist stones and press them down. See if and when the seeds will sprout. Try this with different types of seeds in different pots.
Gently flip a plant onto its side. Watch the plant throughout the day and see if the leaves stretch toward the sun as it makes its way across the sky.