In his historic guide to herbal remedies, 17th-century botanist and physician Nicholas Culpeper remarked that Borage had the power to “expel pensiveness and melancholy”.
To look at its cobalt-blue star-shaped flowers, Culpeper wasn’t wrong, but he wasn’t just referring to its pretty petals.
What is borage used for?
Borage is commonly used as a companion plant and cover crop as it enriches the soil with vital nutrients, assisting in the pest and disease resistance of nearby plants. Borage is also used in mulching and composting, has many culinary uses, and its seed oil is thought to possess some health benefits.
So it can be of use to your crops, lawn, and kitchen cupboard! But this multi-purpose herb can also pose certain health risks when used in excess. Keep reading to find out how you can make the most of borage in your home and garden, plus seed-sowing, planting, and care tips.
How To Use Borage
Borage can either be planted for the purpose of harvesting its edible leaves and flowers or grown primarily to enrich your garden soil and the health of other crops. Let’s learn a little more about borage and how it may be used to the best effect.
|Botanical Name||Borago officinalis|
|Other Names||‘Starflower’; ‘Bee Bush’; ‘Bee-Bread’|
|Annual or Perennial||Annual|
|When To Plant||April/May|
|Preferred Soil||Moist yet well-draining; rich in organic matter|
|Light Requirements||Full/partial sun, ideally in 6-8 hours direct sunlight|
|When To Water||Every few days, enough to maintain evenly-moist soil|
|Mature Size||2ft tall, 1.5ft wide|
|Days Till Harvest||42-56 days|
|Common Uses||Cover crop; companion plant; mulch; compost material; garnish in savory dishes; edible decorations; treatment of skin disorders|
Benefits of Borage in the Garden
- Attracts beneficial pollinators like honeybees and butterflies (hence two of its common nicknames!)
- Repels garden nuisances like Tomato hornworms and Cabbage worms who can’t stand its slightly salty cucumber-like fragrance
- Releases essential minerals into the soil such as Calcium and Potassium, which aid nearby plants in fighting off disease
- Compatible with most plants
- Readily self-seeds
As the foliage of borage is high in nitrogen and its flowers rich in essential plant nutrients, this herb is an excellent candidate for the compost heap as all of this organic matter aids in the pile’s decomposition.
You can also grow borage as a cover crop as its high nutrient content helps to enrich the soil and benefit fellow plants by attracting helpful pollinators to your patch. And once it’s served its purpose as a living crop, borage can make an amazing mulch material to conserve moisture and suppress weeds for other flowering plants!
To get the best possible mulch from your borage plant, author of The Suburban Micro-Farm Amy Stross advises a “cutting back borage just before it flowers as this is when the plant contains the most amount of soil-enriching nutrients.
Either lay the borage cuttings directly on the soil surface or tucked under existing mulch.”
Its fresh cucumber aroma and flavor make borage leaves at home in salad greens, sandwiches, stews, soups, and garnishes in summery drinks like lemonade and cocktails.
Both the leaves and flowers can also be used in ice cubes, jellies, preserves, cooking sauces, or as candied edible decorations in many desserts!
Borage oil has 2-3 times the amount of GLA (gamma-linolenic acid) of the essential oil Evening Primrose and this high concentration of the omega-6 fatty acid is thought to reduce inflammation, relieve stress, and aid allergies, though these benefits are mostly anecdotal.
While its impact on skin ailments is largely inconclusive, a 2010 study found that borage seed oil showed positive results in some participants with atopic dermatitis.
Borage Companion Plants
As above-mentioned, the scent and essential nutrients of the borage herb help various species of neighboring plants and trees fight off disease and garden pests whilst luring in much-needed pollinating insects.
Interplant borage with:
- Cabbages (and other Brassica plants)
- Fruit trees and bushes
Precautions for Using Borage
The leaf, flower, and seed of borage plants contain pyrrolizidine alkaloids or PAs which when consumed in high doses for long periods can be carcinogenic and cause liver damage or worsen existing liver conditions, according to Healthline and a study published in the Journal of Food and Drug Analysis.
According to the University of Rochester Medical Center, the high dose of GLA’s present in Borage oil “can increase or decrease the effects of certain medications,” so always consult your health care provider before taking borage in raw or product form.
As a precaution, pregnant and breastfeeding women should not take any form of borage oil supplement.
How To Grow Borage
Borage seeds (blackish-brown and oblong with a wrinkled grooved texture) should be sown 4 weeks before the last frost date. Sprinkle them lightly and cover seeds with ¼ to ½ an inch of soil/compost.
TIP: Only sow borage seeds in pots if you intend to keep them in containers as the taproot doesn’t respond well to transplanting!
Ideal Growing Conditions
Borage thrives in a full sun planting site but is tolerant of partial shade. Borage also performs best in moderately moist but well-draining soil that’s rich in organic matter like loam, sand, or clay mixed with some well-aged compost to achieve its preferred slightly acidic pH range of 6.0-7.0.
- Borage is drought-tolerant but you should aim to water it enough to keep the soil evenly moist.
- Regular fertilizer won’t be necessary but you can give borage a boost each spring/summer with some compost tea.
- Remove spent flowers to encourage a longer blooming season and prune back plants by half around mid-summer.
- Consider using support stakes as they grow taller for added win protection.
When To Harvest Borage
Within 6-8 weeks of sowing, take fresh young leaves throughout spring and summer that haven’t yet developed bristly hairs using garden scissors and gloves (as the leaves may irritate the skin),
You can also harvest tender new stems – you may want to run a paring knife down the length of harvested stems to remove the prickles before cooking with them!
Growing Borage in Pots
To accommodate its taproot, choose a pot at least 12 inches wide and deep (or larger) and fill containers with 2 parts peat-free potting mix and 1 part coarse potting grit for adequate drainage.
Bring potted borage indoors once temperatures dip below 50°F or place a cloche over the container in mild winter regions.
What Not To Plant With Borage?
Though Borage is considered to be a suitable companion for most crops, its deep taproot and broad foliage may bully smaller competing plants in its space. For this reason, planting small crops such as Basil, Spring onion, Radish, and Watercress with borage is not advisable.
Is Borage Invasive?
Borage is often deemed invasive due to its proficient self-seeding habit, but the seeds are easily identified and removed. They can also be considered an invasive plant if left to fully mature with little maintenance, so it’s important to heavily prune back borage after the flowering stage.
Borage is certainly one versatile herb! Most will choose to grow it as a companion plant due to its soil-enriching qualities and pest-fighting powers for popular crops like Cabbages and Tomatoes.
When used in small amounts, the leaves and flowers make a pleasant addition to savory and sweet dishes. While borage seed oil claims to treat inflammation, stress, and various skin ailments, this is yet to be backed by hard scientific evidence, so always consult a healthcare professional before using it.