Can I plant herbs together in one window box?

Written by
Michael Sullivan
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Companion planting in window boxes saves space while creating healthy herb communities. To get the most from your efforts, plant herbs with compatible requirements. Mediterranean varieties like rosemary and thyme both like dry soil and full sunshine. Such natural companions greatly simplify care.
Another compatible category involves moisture-loving herbs. Parsley, chive, and coriander thrive well together in partial shade conditions. Their soil should be kept moist at all times, but never soggy. These plants promote each other's growth but do not compete eagerly for either nutrients or root space.
Always grow mint separately as it has an invasive root system. Mint runners will quickly choke neighboring plants. Grow it in a separate container with root barriers. This will prevent it from overwhelming tender herbs, such as basil or oregano, that are nearby.
Sun-Loving Groups
- Rosemary + Thyme: Both prefer dry soil and full sun
- Oregano + Sage: Mediterranean herbs needing minimal water
- Lavender + Marjoram: Drought-tolerant pair for hot locations
Moisture Groups
- Parsley + Cilantro: Need consistent moisture and partial shade
- Chives + Chervil: Tolerate cooler conditions and damp soil
- Lemon Balm + Lemon Verbena: Enjoy humid environments
Problematic Combinations
- Mint + Any Herb: Always isolate due to aggressive roots
- Basil + Sage: Different water needs cause stress
- Dill + Fennel: Cross-pollination ruins seed production
Proper spacing in shared containers reduces overcrowding. Allow 4-6 inches of spacing between rosemary plants. Parsley needs 3-4 inches of spacing. If you do not allow spacing, roots crowded together compete for nutrients, resulting in stunted growth and increased risk for disease.
Check your plants' health weekly, looking for signs of incompatibility. Yellow leaves are a sign of too much water. Stunted growth can indicate root competition. If you notice a problem, fix it right away by moving the boxes around or transplanting one of the plants. Container gardening is about prevention vs correction.
Achieving success in window box gardening involves more careful consideration of plant relationships. Planting herbs with similar climatic requirements alongside one another will create vibrant and thriving plant communities. The expected outcome of poor plant pairings is underperformance. Still, successful plant pairings will result in robust arrangements that yield ample harvests from your containers.
Read the full article: 10 Best Window Box Herbs for Your Kitchen