Experiment: Access to Water

Materials (for each group of 3–4 people)

2 identical plants with average water needs. Good plants for this include: pansies, impatiens, petunia.
Sunny outdoor area or a sunny windowsill
Experiment Log (provided)
Measuring cups
Water
Optional: two small cacti/succulents in pots

Steps

Note: See section “Expanding the Activity” for additional elements you may choose to include.

Use the Experiment Log to write a hypothesis for the experiment and to make initial (baseline) measurements of each plant’s height, number of leaves and flowers, and their respective color. These may change during the experiment, so it is important to record these measurements accurately at this time.
Label the plants (one as “water” and one as “no water”)
Place both plants in the same area:- in a sunny location outside or on a sunny windowsill. Note: In this experiment, the amount of water is the only independent variable, so it is important to give both plants equal access to sunlight.
Check the plant labeled “water” every day. Provide this plant with water when the soil begins to dry out. If it rains, be sure to cover the plant labeled “no water.”
Repeat measurements of both plants once a week. Record results on the Experiment Log.
Carry out the experiment for 4-5 weeks and then discuss the results.

Discussion Questions