Hydrotropism, the growth of plant roots toward water, is a fascinating natural phenomenon that can be easily observed in outdoor plant boxes. Certain plants excel at showcasing this behavior, making them ideal for educational or decorative purposes. Here are the best plants to demonstrate hydrotropism outdoors:

1. Peas (Pisum sativum) – Peas are excellent for hydrotropism experiments due to their rapid root growth and clear response to moisture gradients.

2. Sunflowers (Helianthus annuus) – Their robust root systems actively seek water, making them a great choice for visual demonstrations.

3. Beans (Phaseolus vulgaris) – Bean plants exhibit strong hydrotropic responses, with roots visibly bending toward water sources.

4. Corn (Zea mays) – Corn roots grow aggressively toward moisture, showcasing hydrotropism effectively in outdoor settings.

5. Tomatoes (Solanum lycopersicum) – Tomato plants adapt quickly to water availability, making them practical for hydrotropism studies.

For optimal results, use well-draining soil and position water sources unevenly to encourage root movement. Observing these plants in outdoor plant boxes not only highlights hydrotropism but also enhances understanding of plant adaptation and survival strategies.