Yes, you can use an outdoor plant box for a small blueberry bush, provided it meets the plant’s specific needs. Blueberries thrive in well-draining, acidic soil (pH 4.5–5.5), so ensure your plant box has adequate drainage holes and is filled with a suitable soil mix. A container depth of at least 12–18 inches is ideal for root growth.

Place the plant box in a sunny spot, as blueberries require 6–8 hours of sunlight daily. Regular watering is essential to keep the soil moist but not waterlogged. Dwarf or compact varieties like 'Top Hat' or 'Sunshine Blue' are excellent choices for small spaces.

With proper care, your blueberry bush can flourish in an outdoor plant box, offering fresh berries and ornamental appeal for your patio or balcony.