Yes, you can grow dwarf wasabi plants in an outdoor plant box, but it requires careful attention to their specific needs. Wasabi (Wasabia japonica) thrives in cool, shaded environments with consistently moist, well-draining soil. Here’s how to make it work:

1. Choose the Right Location: Wasabi prefers partial to full shade, as direct sunlight can scorch its leaves. Place the plant box in a spot that mimics its natural forest floor habitat.

2. Soil Requirements: Use rich, loamy soil with high organic matter. Ensure the soil stays damp but not waterlogged, as wasabi is sensitive to both drought and standing water.

3. Temperature Control: Dwarf wasabi grows best in temperatures between 46–68°F (8–20°C). In hotter climates, provide extra shade or mist the plants to keep them cool.

4. Watering Routine: Maintain consistent moisture by watering regularly. Mulching helps retain soil moisture and regulate temperature.

5. Harvesting Tips: Patience is key—wasabi takes 12–24 months to mature. Harvest leaves sparingly to avoid stressing the plant.

With the right conditions, your outdoor plant box can yield fresh, homegrown wasabi for culinary delights!