Chemonasty is a fascinating plant response where movement or growth is triggered by chemical stimuli, rather than directional cues like light or gravity. Outdoor plant boxes provide an excellent environment to observe this phenomenon. Here are the best plants to showcase chemonasty:

1. Mimosa pudica (Sensitive Plant): Known for its rapid leaf-folding response when touched or exposed to certain chemicals, this plant is a classic example of chemonasty.

2. Venus Flytrap (Dionaea muscipula): While primarily known for its mechanosensitive traps, it also responds to chemical cues, making it ideal for demonstrating chemonasty.

3. Drosera (Sundew): These carnivorous plants react to chemical stimuli by curling their sticky tentacles around prey.

4. Oxalis spp. (Wood Sorrel): Some species exhibit leaf movements in response to chemical changes in their environment.

For optimal results, place these plants in well-draining soil and monitor their responses to mild chemical triggers like diluted vinegar or sugar solutions. Outdoor plant boxes allow for natural observations, making them perfect for educators and gardening enthusiasts alike.