Yes, you can absolutely grow fennel in an outdoor plant box! Fennel is a versatile herb that thrives in containers, making it an excellent choice for small gardens, balconies, or patios. Here’s how to ensure success:

1. Choose the Right Box: Opt for a deep plant box (at least 12 inches) to accommodate fennel’s long taproot. Ensure it has drainage holes to prevent waterlogging.

2. Soil Requirements: Use well-draining, nutrient-rich soil with a slightly acidic to neutral pH (6.0–7.0). Adding compost can boost growth.

3. Sunlight: Fennel loves full sun—aim for 6–8 hours of direct sunlight daily.

4. Watering: Keep the soil consistently moist but not soggy. Water deeply when the top inch of soil feels dry.

5. Spacing: If planting multiple fennel plants, space them 12–18 inches apart to avoid overcrowding.

Fennel is low-maintenance but watch out for pests like aphids. Harvest the bulbs, leaves, or seeds once mature, and enjoy this flavorful herb in your cooking! With proper care, your outdoor plant box can yield a bountiful fennel harvest.