Growing dwarf allspice plants (Pimenta dioica) in an outdoor plant box is entirely possible with the right conditions. These compact spice plants thrive in warm climates but can adapt to container gardening if given proper care.

Key Requirements:

1. Sunlight: Dwarf allspice plants need at least 6 hours of sunlight daily. Place your plant box in a sunny spot, preferably with partial shade in hotter regions.

2. Soil: Use well-draining, slightly acidic soil enriched with organic matter. A mix of potting soil and compost works well.

3. Watering: Keep the soil consistently moist but not waterlogged. Ensure your plant box has drainage holes to prevent root rot.

4. Temperature: Allspice plants prefer temperatures between 60-85°F (15-29°C). In cooler climates, move the plant box indoors during winter.

5. Fertilization: Feed with a balanced fertilizer every 4-6 weeks during the growing season for optimal growth.

Benefits of Container Growing:

- Easier control over soil and moisture conditions.

- Flexibility to move plants based on weather changes.

- Ideal for small spaces like balconies or patios.

With proper care, your dwarf allspice plant can flourish in an outdoor plant box, providing aromatic leaves and berries for culinary use. Happy gardening!