Yes, you can grow a small weigela in an outdoor plant box! Weigelas are versatile flowering shrubs that adapt well to container gardening, making them a great choice for patios, balconies, or small gardens. Here’s how to ensure success:

1. Choose the Right Variety: Opt for compact or dwarf weigela varieties like 'Midnight Wine' or 'Spilled Wine,' which thrive in confined spaces.

2. Select a Suitable Plant Box: Ensure the box is at least 18-24 inches deep and wide, with drainage holes to prevent waterlogging.

3. Use Quality Soil: A well-draining potting mix enriched with organic matter supports healthy root growth.

4. Provide Adequate Sunlight: Weigelas need at least 6 hours of sunlight daily for optimal blooming.

5. Water and Fertilize Regularly: Keep the soil moist but not soggy, and feed with a balanced fertilizer in spring.

With proper care, your weigela will reward you with vibrant blooms and lush foliage, even in a plant box!