If you're considering growing a small summersweet (Clethra alnifolia) in an outdoor plant box, the answer is yes—with the right conditions. Summersweet is a versatile shrub known for its fragrant summer blooms and adaptability to various environments, including container gardening.

To ensure success, choose a spacious plant box with adequate drainage to prevent waterlogging. Summersweet thrives in moist, well-draining soil and prefers partial shade to full sun, depending on your climate. Regular watering is essential, especially during dry spells, as the plant dislikes drying out completely.

Additionally, fertilize lightly in early spring to encourage healthy growth and vibrant blooms. Pruning isn’t strictly necessary but can help maintain a compact shape if space is limited. With proper care, your summersweet will flourish in an outdoor plant box, adding beauty and fragrance to your patio or garden.