What Not to Plant With Borage: The Complete Companion Planting Guide

Borage (Borago officinalis) is a versatile herb that can benefit many plants when used thoughtfully in companion planting. With its vibrant blue flowers that attract pollinators and pest-repelling abilities, borage deserves a spot in both ornamental and edible gardens. However, some plants are poor companions for borage due to competition or other incompatibilities. Knowing what not to plant with borage is key for success

In this complete guide, we’ll cover:

• The benefits of planting borage with other plants
• The worst companion plants for borage and why they don’t mix
• How to successfully pair borage with the right plants
• Troubleshooting companion planting problems with borage
• Tips for maximizing the advantages of borage

Why Borage Makes a Great Companion Plant

With star-shaped blue blooms that shine all summer long borage provides some excellent benefits to nearby plants when used effectively

• Attracts pollinators: The nectar-rich flowers draw in bees, butterflies, and other pollinating insects. These pollinators can then visit and fertilize the flowers of other plants.

• Repels pests: Borage deters common vegetable pests like tomato hornworms, cabbage worms, and flea beetles through aromatic compounds in its tissues.

• Improves growth: Nearby plants like strawberries and tomatoes often have better flavor and increased yields when partnered with borage.

• Helps soil: Borage brings nutrients like potassium and calcium to the soil surface through deep taproots. As a green manure, it can improve soil structure and fertility.

• Provides ground cover: The low-growing foliage can act as living mulch, shading soil to conserve moisture and prevent weeds.

With benefits like these, it’s clear why borage deserves a central spot in your companion planting schemes. But certain plants just aren’t the right match.

What Not to Plant With Borage

While borage pairs nicely with many crops, there are a few key plants that should be avoided when companion gardening with borage:

1. Root Vegetables

Staple root crops like carrots, radishes, turnips, and potatoes don’t mix well with spreading borage. The extensive roots systems of these vegetables compete with borage for water and nutrients. And the prickly borage stems and foliage can slow development of the underground edible roots. For best results, plant borage and root crops in separate garden beds.

2. Short, Dense Herbs

Delicate herbs like cilantro, parsley, thyme, and chives can struggle when borage towers over them. The rampant borage growth blocks light and crowds out lower-growing herbs. Dill often bolts or goes to seed prematurely when shaded by borage. For herbs and borage to coexist, allow lots of space between plants.

3. Onions and Garlic

Onions and garlic prefer consistent moisture and full sun. When borage competes for water or shades the bulbs, growth suffers. Borage may also harbor onion maggots, leek moths, and other allium pests. Keep borage at least 2 feet away from onions, garlic, leeks, and chives.

4. Lettuce and Spinach

Quick-growing leafy greens need moist soil and unfiltered sun. They bolt or become stringy and bitter when crowded and shaded by spreading borage foliage. Prevent competition by planting borage and greens in separate beds or wide rows.

5. Legumes

Nitrogen-fixing beans, peas, soybeans, and other legumes add nitrogen to the soil. But borage can take up that nitrogen greedily for its own rapid growth. Sparse or yellowing legume plants indicate nitrogen theft. Avoid planting borage amidst legumes.

6. Vining Crops

Sprawling vines of cucurbits like cucumbers, melons, pumpkins, and squash often tangle with borage’s prickly stems. And the upright borage growth blocks sunlight from reaching the lower vines. Trellis vining crops away from borage or use physical barriers between plants.

How to Plant Borage with Companions

Now that you know what not to plant with borage, let’s look at how to successfully pair borage with beneficial companion plants:

• Tomatoes – Plant borage around tomatoes to boost pollination, improve flavor, and deter pests like hornworms. Allow at least 12 inches between plants.

• Squash – Use borage as a border around zucchini, pumpkins, and winter squash. It repels squash bugs and increases pollination.

• Grapes – Grow borage underneath grapes as a living mulch. It suppresses weeds, conserves moisture, and attracts beneficial insects.

• Brassicas – Alternate borage with broccoli, cabbage, kale and other brassicas in the same row. Borage deters cabbage worms.

• Strawberries – Use borage as an edging plant around strawberry beds. It enhances fruit quality and draws pollinators for better yields.

• Herbs – Plant borage near rosemary, dill, cilantro, and basil but not directly amidst them. It attracts pollinators but can overtake small herbs.

Troubleshooting Companion Planting Problems

Even with ideal pairings, borage sometimes causes issues:

Poor herb growth – If thyme, parsley or cilantro becomes stunted and leggy, borage may be shading them. Thin or prune back encroaching borage.

Reduced crop yields – Low productivity of eggplant, beans or other crops can indicate nutrient or water theft by aggressive borage. Uproot some borage plants to reduce competition.

Vining crop damage – If cucurbit vines are crushed and damaged, separate borage and vines with a trellis or cage. Borage’s prickly stems can harm tender vines.

Lack of germination – Borage’s thick foliage and roots block seeds from sprouting. Gently move borage plants back and re-sow seeds.

With vigilant observation, you can keep your borage companion planting in balance. Intervene at the first sign of problems.

Maximizing the Benefits of Borage

Here are some tips for using borage effectively as a companion plant:

• Start seeds indoors 6-8 weeks before your last spring frost for stronger transplants. Harden off before planting out.

• Allow at least 12 inches between borage and companion plants to prevent crowding and competition.

• Grow borage upwind of herbs and vegetables to deter pests like cabbage moths being blown in.

• Remove spent borage plants after flowering to prevent self-seeding. Borage can become weedy.

• Add chopped borage plants to compost piles. The high mineral content benefits your garden soil.

• Plant borage near garden edges and walkways to attract beneficial pollinators into your growing area.

With smart companion planting, borage can boost the health and productivity of your entire garden. Just beware of pairing this aggressive grower with the wrong plants. Use borage to its full advantage by giving it the space, site, and soil it needs to thrive alongside complementary plants.