Nutational chemotropism is a fascinating plant behavior where stems or tendrils exhibit spiral or swaying movements in response to chemical gradients, light, or touch. Outdoor plant boxes provide an excellent environment to observe this phenomenon. Here are some of the best plants to showcase nutational chemotropism:

1. Sweet Pea (Lathyrus odoratus) – Known for its delicate tendrils that actively seek support, sweet peas display pronounced nutational movements as they climb.

2. Morning Glory (Ipomoea purpurea) – This fast-growing vine twists and turns its stems to latch onto structures, making it ideal for observing chemotropic responses.

3. Cucumber (Cucumis sativus) – Cucumber vines exhibit strong nutational growth, with tendrils that coil tightly around supports in response to touch and chemical cues.

4. Passionflower (Passiflora spp.) – Its vigorous climbing habit and responsive tendrils make it a great candidate for studying tropic movements.

5. Hop (Humulus lupulus) – A robust climber, hops showcase helical nutation as their stems spiral upward in search of sunlight.

For optimal results, ensure your outdoor plant boxes have trellises or supports to encourage climbing. Regular watering and balanced fertilization will enhance growth and nutational activity. Observing these plants can provide valuable insights into plant behavior and adaptive growth strategies.