If you're considering growing a small liquidambar tree in an outdoor plant box, the answer is yes—but with some important considerations. Liquidambars, known for their stunning fall foliage, can thrive in containers if given proper care.

Key Factors to Consider:

1. Size of the Plant Box: Liquidambars have extensive root systems. Choose a large, sturdy box (at least 24 inches deep and wide) to accommodate growth.

2. Drainage: Ensure the box has adequate drainage holes to prevent root rot.

3. Soil Quality: Use well-draining, nutrient-rich soil to support healthy growth.

4. Sunlight: Liquidambars need full sun to partial shade—place the box in a sunny spot.

5. Watering: Keep the soil consistently moist but not waterlogged.

Long-Term Care:

- Prune roots and branches every few years to manage size.

- Repot or refresh soil every 2-3 years to maintain nutrients.

- Protect from extreme cold by moving the box indoors or insulating it in winter.

With the right setup, an outdoor plant box can be a great way to enjoy a liquidambar in small spaces like patios or balconies. Just be prepared for regular maintenance to keep your tree healthy and vibrant.