Kale is a popular, nutrient-dense leafy green that thrives in many garden settings. Gardeners often use companion planting, a strategic technique that pairs kale with other plants for mutual benefit, to achieve a successful harvest. This practice creates a healthier micro-ecosystem, improving the vigor of the kale crop and maximizing productivity.
The Core Mechanisms of Kale Companion Planting
Companion planting leverages natural biological relationships to protect and nourish brassicas like kale. A primary function is pest management, achieved through scent masking and beneficial insect attraction. Aromatic plants release compounds that confuse scent-driven pests, such as the cabbage moth, making it difficult for them to locate the kale.
Other companions improve soil health by enriching the environment with necessary nutrients. Legumes fix atmospheric nitrogen into a form kale can absorb, supporting the plant’s high demand for this nutrient. Deep-rooted plants also break up compacted soil, improving drainage, and making sub-surface minerals available to the shallower roots of the kale.
Another benefit is microclimate management. Some companions provide necessary shade during intense heat or act as a living mulch to retain soil moisture and suppress weed growth.
Specific Plant Companions That Boost Kale Health
Many herbs and flowers serve as effective pest deterrents for kale. Dill, with its strong fragrance, repels common pests while attracting beneficial insects like parasitic wasps and ladybugs, which prey on aphids and cabbage worms. Marigolds are another highly effective choice, as their roots release substances that repel nematodes in the soil, and their scent helps confuse other harmful insects.
Specific vegetables offer support through soil enhancement or as sacrificial protectors. Bush beans are excellent nitrogen fixers, depositing the nutrient directly into the soil where kale can use it to develop large, healthy leaves. Radishes and nasturtiums can be used as trap crops, drawing pests like flea beetles and aphids away from the kale, allowing the main crop to grow undisturbed.
Root vegetables like carrots and beets are good companions because they occupy a different soil level than kale’s shallow root system, minimizing competition for resources. These underground growers also help to loosen the soil as they expand, which benefits the kale’s root growth and the overall soil structure. Sweet alyssum is a low-growing flower that conserves moisture and attracts hoverflies, which are natural predators of aphids.
Plants That Should Never Be Planted Near Kale
Certain plants can hinder kale’s growth by competing aggressively for nutrients or by acting as a shared host for pests and diseases. Other brassicas, including broccoli, cabbage, and cauliflower, are poor neighbors because they share vulnerabilities to pests like the cabbage moth and diseases like clubroot. Planting them in close proximity concentrates the pest population, increasing the risk of a widespread infestation.
Heavy feeders that require large amounts of nitrogen and water, such as tomatoes and corn, compete directly with kale for limited soil resources. Tomatoes can shade out the kale too much in smaller garden spaces, and both plants attract similar pests. Pole beans, while nitrogen-fixing, can grow tall enough to severely overshadow kale plants, reducing the light exposure needed for robust leaf production.
Strawberries are best kept away from kale because they attract slugs and spider mites, pests that readily damage the leaves. Sunflowers are also avoided near kale, as their large, dense canopies create too much shade, stunting the kale’s growth.