Nutational radionasty is a fascinating phenomenon where plants exhibit rhythmic, spiral movements as they grow, often in response to environmental stimuli like light or gravity. Outdoor plant boxes provide an excellent setting to observe this natural behavior. Here are some of the best plants to showcase nutational radionasty:

1. Morning Glory (Ipomoea purpurea): Known for its rapid twining growth, morning glory vines spiral around supports, displaying clear nutational movements as they seek sunlight.

2. Sweet Pea (Lathyrus odoratus): This climbing plant exhibits elegant nutation as its tendrils reach out and coil around structures, making it ideal for outdoor boxes.

3. Runner Beans (Phaseolus coccineus): Their vigorous growth and twisting stems demonstrate nutational radionasty vividly, especially when trained on trellises.

4. Passionflower (Passiflora spp.): With its intricate tendrils and climbing habit, passionflower showcases rhythmic movements as it navigates its environment.

5. Hops (Humulus lupulus): This fast-growing vine spirals clockwise around supports, offering a striking example of nutational radionasty in action.

To enhance observations, place your outdoor plant box in a sunny spot and provide vertical supports like trellises or stakes. Regularly document growth patterns to witness the captivating dance of nutational radionasty in these dynamic plants.