Creating a thriving patchouli garden in outdoor plant boxes requires careful selection of companion plants that complement its growth habits and environmental needs. Patchouli (Pogostemon cablin) thrives in partial shade and moist, well-draining soil, making it ideal for pairing with other shade-tolerant and moisture-loving species.

1. Mint (Mentha spp.) – Aromatic and fast-growing, mint helps deter pests while enjoying similar soil conditions.

2. Lemon Balm (Melissa officinalis) – This fragrant herb attracts pollinators and thrives in partial shade.

3. Ferns (Nephrolepis spp.) – Their lush foliage provides a beautiful contrast and thrives in humid, shaded environments.

4. Caladiums – These colorful foliage plants add visual interest and prefer the same moist, shaded conditions.

5. Sweet Woodruff (Galium odoratum) – A low-growing ground cover that flourishes in shade and enhances soil moisture retention.

For optimal growth, ensure your plant boxes have adequate drainage and organic-rich soil. Regular pruning of patchouli and its companions will maintain airflow and prevent overcrowding. By selecting the right plants, you can create a vibrant, aromatic patchouli garden that thrives in outdoor plant boxes.