Borage (Borago officinalis) is a versatile annual herb known for its vibrant blue, star-shaped flowers and slightly fuzzy leaves. Historically used in traditional medicine and culinary practices, it is now widely recognized in gardening for its beneficial role in companion planting.
Why Borage Excels as a Companion Plant
Borage excels as a companion plant due to its ability to attract beneficial insects. Its bright blue flowers draw in bees, butterflies, and other pollinators, increasing fruit set and yield for nearby fruiting plants. The plant’s continuous nectar production ensures a steady food source for these pollinators throughout the growing season.
Borage also helps deter common garden pests. It can repel pests like tomato hornworms and cabbage worms. Beneficial insects such as parasitic wasps, hoverflies, and lacewings are drawn to borage, and these natural predators feed on harmful pests, providing a chemical-free pest control method.
Borage also contributes to soil health through its deep taproot system. This root structure draws nutrients from deeper soil layers, making them available to shallower-rooted plants as borage leaves decompose. The decomposition of borage leaves and stems enriches the soil with organic matter, improving fertility and nutrient availability. Its ability to break up compacted soil further enhances aeration and water infiltration.
Ideal Companions for Borage
Borage pairs well with a variety of garden plants, enhancing their growth, flavor, and pest resistance. Tomatoes benefit significantly from borage, which helps deter tomato hornworms and can lead to improved growth and flavor.
Strawberries also thrive when planted alongside borage. The attraction of numerous pollinators to borage can lead to increased fruit production in strawberries. Additionally, borage may help deter pests like aphids that commonly affect strawberry plants.
For members of the squash family, including cucumbers, melons, and zucchini, borage is an excellent companion. It attracts the pollinators needed for fruit development and can help deter pests like squash bugs and cucumber beetles. The large leaves of borage can also provide shade, helping to keep the soil moist and cool for these plants.
Cabbage and other brassicas, such as broccoli and kale, are protected by borage’s ability to deter cabbage worms and other common brassica pests by attracting beneficial insects. Legumes like beans and peas also benefit from borage, primarily through increased pollination and potentially improved growth.
Fruit trees and bushes also gain from borage’s presence. Planting borage nearby attracts pollinators, which is beneficial for fruit blossom pollination and can lead to higher yields. Certain herbs, including dill, parsley, and thyme, are considered good companions, often experiencing general growth enhancement.
Plants to Avoid with Borage
While borage is largely beneficial, some pairings are less ideal. Root vegetables like carrots, potatoes, and turnips may struggle when planted too close. Borage’s vigorous root system can compete for water and nutrients, and some sources suggest chemical interference, potentially hindering their growth.
Fennel is another plant some sources suggest avoiding near borage, as both attract similar beneficial insects, potentially leading to competition for pollinators. Borage may also inhibit the growth of certain herbs like basil or rosemary, though the extent of such allelopathic effects can vary. Due to its sprawling and self-seeding nature, borage can overwhelm very small, delicate plants, so caution is advised.
Integrating Borage into Your Garden Design
Incorporating borage into your garden for companion planting is straightforward. Borage is easy to grow directly from seed and readily self-seeds, often reappearing each year. Seeds can be sown directly into the garden bed in spring after the last frost.
Strategic placement is key to maximizing its companion planting benefits. Interplanting borage directly among vegetables or planting it as a border around beds allows for close interaction with its companion plants. When planting, ensure adequate spacing, as borage can grow quite large, reaching up to 2-3 feet tall.
Maintenance for borage in a companion planting scheme is minimal. Allowing the plant to flower is important to attract pollinators and beneficial insects. While borage self-seeds vigorously, excess seedlings can be easily removed if they appear in unwanted areas. Light pruning can be done if the plant becomes too dominant. The leaves and flowers of borage are edible and can be harvested for culinary use without hindering its benefits to nearby plants.