Companion planting involves placing different plant species near each other to create a mutually supportive environment. This strategy is based on the idea that certain plant pairings offer benefits, leading to a healthier and more productive garden overall. For strawberries, which are susceptible to various pests and diseases, strategic planting can significantly improve health and fruit yield. Arranging plants thoughtfully leverages natural synergies, helping to deter unwanted organisms and enhance soil quality.
Companion Plants for Protection and Pest Control
The most immediate benefit of companion planting is the natural defense it offers against common garden pests and diseases. Certain plants release powerful scents or chemical compounds that actively repel harmful insects, while others attract beneficial predators. This protective synergy is essential for a healthy strawberry patch.
The Allium family, including onions, chives, and garlic, is a well-regarded companion for defense against fungal issues and common pests. These plants emit sulfur compounds that help suppress fungal diseases like fusarium wilt. The pungent aroma of alliums also works as a natural deterrent, repelling insects such as aphids, slugs, and snails that are drawn to the strawberry foliage.
Marigolds, particularly French marigold varieties, offer subterranean protection for strawberry roots. They exude a substance toxic to root-knot nematodes, microscopic roundworms that severely damage the root system. Planting French marigolds throughout the patch creates a protective barrier against these soil-borne pests.
Certain herbs actively recruit beneficial insects to the garden. Thyme, when flowering, attracts predatory insects such as hoverflies and parasitic wasps, whose larvae feed on common strawberry pests like aphids. Sage releases strong-smelling compounds that mask the attractive scent of ripening strawberries, making it harder for pests like flea beetles to locate the crop. Basil also repels a wide range of pests, including thrips and whiteflies, due to compounds present in its oil.
Planting Partners That Boost Growth and Flavor
Beyond pest management, other companion plants contribute to the vigor and productivity of strawberries through nutritional or structural support. These partners focus on improving soil health, attracting pollinators, and providing favorable growing conditions.
Legumes, such as bush beans and peas, improve the nutritional environment for strawberries. These plants host nitrogen-fixing bacteria in root nodules, which capture atmospheric nitrogen and convert it into a usable form. As legumes grow, this fixed nitrogen becomes available in the soil, providing a nutrient boost that supports healthy leaf growth and fruit production.
Borage, an herb with distinctive blue flowers, is cited for its positive influence on strawberries. It is highly effective at attracting essential pollinators, like honeybees, which are needed for successful fruit set and development. Some gardeners believe that borage also improves the flavor and yield, possibly by releasing trace minerals as the plant decomposes.
Caraway is an aromatic herb that contributes to the health of the patch by attracting natural predators, specifically parasitic flies and wasps, which prey on pests like aphids and mites. The foliage of low-growing plants like spinach and lettuce functions as a living mulch, suppressing weeds and retaining soil moisture around the shallow roots. This structural support allows strawberries to utilize resources more efficiently.
Specific Plants That Should Not Be Paired With Strawberries
Just as some plants offer benefits, others can actively harm strawberries and should be avoided entirely. These detrimental pairings often lead to severe competition for resources or the spread of diseases.
The Brassica family, which includes cabbage, broccoli, cauliflower, and kale, should be kept separate from strawberries. These vegetables are considered “heavy feeders” that require large amounts of nutrients to support their rapid growth. When planted too close, brassicas aggressively compete for soil nutrients, ultimately stunting growth and reducing yield.
A serious threat comes from the Solanaceae, or nightshade family, which includes tomatoes, potatoes, peppers, and eggplants. These plants host the soil-borne fungus Verticillium dahliae, the cause of Verticillium wilt, which is highly damaging to strawberries. The fungus invades the water-conducting tissue, causing the outer leaves to wilt and die, limiting the plant’s ability to survive and produce fruit.
This fungal pathogen can persist in the soil for a long time, often 25 years or more, even after host plants have been removed. Therefore, it is advised to avoid planting strawberries in any location that has hosted nightshades within the last three to five years. Understanding the relationships between plants is necessary for cultivating a successful strawberry patch.