Nutational thigmotropism is a fascinating plant movement where stems or tendrils respond to touch by coiling or bending, aiding climbing plants in anchoring themselves. Outdoor plant boxes provide an excellent environment to observe this phenomenon. Here are the best plants to showcase nutational thigmotropism:

1. Sweet Pea (Lathyrus odoratus) – Known for its delicate tendrils that actively wrap around supports, making it perfect for studying thigmotropic responses.

2. Morning Glory (Ipomoea purpurea) – This fast-growing vine exhibits pronounced nutational movements, spiraling around structures with ease.

3. Cucumber (Cucumis sativus) – Its tendrils are highly sensitive to touch, quickly coiling around nearby objects for support.

4. Passionflower (Passiflora spp.) – Features aggressive tendrils that demonstrate strong thigmotropic behavior, ideal for outdoor observations.

5. Hops (Humulus lupulus) – A vigorous climber with twining stems that showcase nutation as they seek vertical support.

For optimal results, ensure your plant boxes have trellises or stakes to encourage climbing. Regular watering and sunlight will enhance growth and movement visibility. Observing these plants can provide valuable insights into plant biomechanics and adaptive behaviors.