Plants have evolved adaptations that allow them to ‘move’. Not in the sense that they uproot and walk away, but in other ways. Plants can move toward or away from water, the sun, and in response to gravity! This is called tropism.
What is Tropism?
Tropism: the means by which a plant grows towards or away from stimuli
Stimuli: a thing or event that evokes/influences a functional reaction
Garden Class Activity
During class, students split up into groups and search for examples of tropism in the garden. These include:
- Thigmotropism: growth or movement in response to touch
- Hydrotropism: growth or movement in response to water (towards or away from moisture)
- Heliotropism: “sun tracking” – growth or movement in response to the sun’s location
- Gravitropism: growth or movement in response to gravity
Once all groups have found their example, each group will share what they found and how it is a type of tropism. These might include plants growing up trellises, toward sunshine, or toward a water source. We have many vining plants in our gardens include green beans, peas, watermelon, ipu, and lilikoi, which make great examples of tropism.