Gravitropism, the growth response of plants to gravity, is a fascinating phenomenon that can be easily observed in outdoor plant boxes. Certain plants are particularly effective for demonstrating this natural behavior due to their pronounced root or shoot growth patterns. Here are some of the best plants to showcase gravitropism in outdoor settings:

1. Sunflowers (Helianthus annuus) – Sunflowers exhibit strong gravitropic responses, with roots growing downward and stems bending upward toward light (phototropism). Their rapid growth makes them ideal for experiments.

2. Peas (Pisum sativum) – Pea plants are classic examples for studying gravitropism, as their roots and shoots respond clearly to gravitational cues. They thrive in plant boxes and are easy to grow.

3. Radishes (Raphanus sativus) – Radishes develop robust taproots that grow straight downward, making them perfect for observing root gravitropism. Their fast germination is an added advantage.

4. Beans (Phaseolus vulgaris) – Bean plants display distinct gravitropic behavior, with roots growing downward and shoots curving upward. Their large seeds are great for educational purposes.

5. Corn (Zea mays) – Corn seedlings are excellent for demonstrating both gravitropism and phototropism, as their roots and shoots respond vividly to gravity and light.

For optimal results, ensure your outdoor plant boxes have loose, well-draining soil and adequate sunlight. Regularly document the growth patterns to observe how these plants adapt to gravitational forces. Whether for educational projects or personal curiosity, these plants offer a captivating glimpse into the wonders of plant biology.