Yes, you can grow a small Pieris (Pieris japonica) in an outdoor plant box, provided you meet its basic growing requirements. Pieris, also known as Japanese Andromeda, is a compact evergreen shrub that thrives in well-draining, acidic soil. When planting in a container, choose a spacious plant box with drainage holes to prevent waterlogging.

Place the box in a location with partial shade to protect the plant from harsh afternoon sun, especially in warmer climates. Regular watering is essential to keep the soil moist but not soggy. Fertilize lightly in spring with an acid-loving plant formula to encourage healthy growth and vibrant foliage.

With proper care, a small Pieris can flourish in an outdoor plant box, adding year-round beauty to patios, balconies, or garden spaces. Just ensure winter protection in colder zones, as container plants are more vulnerable to freezing temperatures.