Companion planting is a gardening method where different plants are grown in close proximity to benefit one another. These benefits can include deterring pests, attracting beneficial insects, improving soil health, or optimizing growth. Rue, or Ruta graveolens, is a perennial herb known for its strong aroma and distinctive blue-green foliage, making it a candidate for this practice.
Understanding Rue’s Role in the Garden
Rue serves as a companion plant primarily through its potent aromatic properties. Its unique compounds, such as rutin and coumarin, create a strong, pungent scent. This aroma deters various garden pests, including Japanese beetles, aphids, slugs, snails, and flea beetles. It can also confuse other herbivores, discouraging them from damaging nearby plants.
Beyond pest deterrence, rue supports beneficial insects. Its yellow flowers, which bloom from June to September, attract various pollinators like bees and wasps. Rue is a host plant for the caterpillars of several swallowtail butterflies, including the black swallowtail, anise swallowtail, and giant swallowtail. Additionally, rue possesses allelopathic properties, releasing compounds into the soil that inhibit the growth of certain weeds and neighboring plants.
Beneficial Companions for Rue
Several plants can benefit significantly when grown near rue. Roses are a classic example; planting rue nearby helps deter common rose pests like Japanese beetles and aphids. The strong scent of rue creates an invisible barrier, protecting roses from these damaging insects.
Raspberries also thrive with rue as a companion, helping to keep aphids and other beetles away from the canes. Certain vegetables, such as onions, benefit from rue’s protective properties by deterring onion fly larvae. Alpine strawberries are another suitable companion, as rue can help repel aphids and slugs. Lavender, a Mediterranean herb, also grows well alongside rue, sharing similar growing conditions.
Plants to Avoid Near Rue
While rue offers many advantages, it also has negative interactions with certain plants due to its allelopathic compounds and differing environmental needs. Basil should not be planted near rue, as rue can inhibit its growth and alter its flavor. This incompatibility is also due to basil’s preference for moist soil, while rue thrives in drier conditions.
Brassicas, such as cabbage, are unsuitable companions for rue. Rue’s allelopathic properties can stunt their growth. Additionally, cabbage prefers rich, moist soil, which contrasts with rue’s requirement for well-drained, less fertile soil. Cucumbers should also be kept separate from rue, as rue’s compounds can inhibit their growth. Sage is another herb that does not grow well near rue.
Integrating Rue into Your Garden
Strategic placement of rue is important to maximize its companion planting benefits while minimizing any negative interactions. Rue prefers full sun and thrives in well-drained soil that is not overly rich. It can be planted as a border around susceptible plants like roses or raspberries. You can also intersperse rue plants within garden beds, ensuring adequate spacing of about 1 to 2 feet between individual rue plants.
When incorporating rue, consider its growth habit as a semi-woody shrub that typically reaches 2 to 3 feet in height and width. While relatively low-maintenance once established, ensuring rue has its preferred dry conditions will help it thrive and maintain its pest-repelling potency. Regular pruning can also encourage bushy growth and maintain its desired shape.