Thermotropism, the growth or movement of plants in response to temperature changes, is a fascinating phenomenon to observe in outdoor plant boxes. Certain plants exhibit this behavior more prominently, making them ideal for educational or experimental gardening. Here are some of the best plants to demonstrate thermotropism:

1. Sunflower (Helianthus annuus) – Known for heliotropism (a form of thermotropism), sunflowers track the sun’s movement, adjusting their orientation to maximize heat and light absorption.

2. Mimosa Pudica (Sensitive Plant) – While primarily known for thigmonasty (response to touch), it also shows subtle thermotropic responses by folding leaves in cooler temperatures.

3. Tulips (Tulipa spp.) – These flowers open and close in response to temperature shifts, making them excellent for observing thermotropic behavior.

4. Marigolds (Tagetes spp.) – Their petals respond to heat by opening wider in warm conditions and closing slightly when cooler.

5. Bean Plants (Phaseolus spp.) – Young bean shoots exhibit thermotropic growth, bending toward warmer surfaces like sun-heated walls or rocks.

For optimal results, place your outdoor plant boxes in areas with varying sunlight exposure and monitor how these plants react to temperature fluctuations. This setup not only highlights thermotropism but also enhances your garden’s visual appeal. Experiment with different species to compare their responses and deepen your understanding of plant behavior.