Peppermint (Mentha piperita) is a fragrant herb valued for its refreshing aroma and many uses in the garden. The practice of companion planting involves strategically pairing different species to create a mutually beneficial environment. This technique aims to enhance growth, improve overall plant health, and manage garden pests without resorting to chemical interventions. Understanding how peppermint interacts with its neighbors is important for maximizing its benefits while managing its challenging growth habits. Successful gardening with peppermint relies on recognizing which plants thrive in its presence and which suffer from its unique characteristics.
Peppermint’s Role as a Garden Protector
Peppermint earns its status as a garden ally primarily through the potent volatile oils concentrated within its leaves and stems. These aromatic compounds, particularly menthol, release a powerful scent that acts as a natural deterrent to numerous common garden pests. The strong odor works by confusing certain insects, masking the scent of nearby host plants and making it difficult for them to locate a feeding site.
This protective function extends to repelling various unwelcome visitors, including aphids, ants, and flea beetles. The plant also attracts beneficial insects, such as bees and butterflies, when it flowers, which aids in the overall pollination of the garden. Peppermint is a vigorous grower that prefers rich, consistently moist soil. Managing the plant’s fast growth habit is a precondition for realizing its protective benefits without compromising the health of adjacent crops.
Specific Plants That Thrive Alongside Peppermint
Many vegetables benefit significantly from the proximity of peppermint, mainly due to its pest-repelling scent. Members of the Brassica family, such as cabbage, broccoli, and kale, are particularly good companions. Planting peppermint near these crops helps to deter the cabbage moth, whose larvae (cabbage worms) can rapidly defoliate the plants. The confusing aroma protects the vulnerable leaves of these vegetables.
Tomatoes and eggplants also thrive when situated near peppermint, as the herb helps control common pests like aphids and flea beetles. The protection extends to root crops, where peppermint is effective at repelling the carrot root fly. Furthermore, gardeners often place peppermint near roses, reporting that the herb helps improve the roses’ health and reduces aphid infestations.
To ensure these positive interactions occur without negative consequences, peppermint must be physically contained. The most effective method is planting the peppermint in a submerged container, such as a plastic pot, with the rim slightly above the soil line. This barrier prevents the herb’s aggressive underground rhizomes from spreading into adjacent beds and competing for water and nutrients. Positioning the contained peppermint nearby allows its scent to benefit the target plants without risking root competition.
Plants That Should Be Kept Away From Peppermint
The primary reason to keep certain plants away from peppermint is its aggressive, invasive root system, which spreads horizontally through rhizomes. If planted directly into a garden bed, peppermint will quickly colonize the area, outcompeting smaller or slower-growing plants for resources like water and nutrients. This aggressive behavior can stunt the growth of even robust neighbors.
Delicate herbs, especially those that prefer drier soil conditions, are particularly incompatible with the moisture-loving mint. Thyme, rosemary, and lavender prefer well-drained environments, making them poor matches for peppermint, which demands consistently damp soil. Growing these herbs near peppermint creates a struggle for resources that inevitably favors the more vigorous mint.
Some herbs are also susceptible to flavor taint, potentially absorbing the strong menthol aroma and altering their delicate taste profile. While some sources suggest basil can be a companion, its strong requirement for nutrients and its vulnerability to being overshadowed make it a risky choice. Other herbs with mild flavors, like parsley, are best planted separately to prevent both competition and interference with their aroma.