Borage (Borago officinalis) is one of those rare plants that earns its place in the garden several times over. Also known as starflower, it’s a fast-growing annual herb native to the Mediterranean region and has been cultivated for centuries for its beauty, flavor, and traditional medicinal uses. Hardy across USDA zones 2 through 11 as an annual, borage thrives almost anywhere it’s given a chance to grow and will often reseed itself so reliably that it behaves like a perennial in many gardens.

The plant produces loose, sprawling mounds of foliage that can reach 2 to 3 feet tall and nearly as wide. Its leaves and stems are covered in soft, silvery hairs that give the whole plant a slightly frosted appearance. But the real showstopper is the flowers. Borage blooms from early summer through fall, producing clusters of vivid, star-shaped blossoms in a brilliant sky blue that’s nearly impossible to find elsewhere in the herb garden. Each five-petaled flower features a distinctive cone of dark stamens at its center, making it irresistible to bees and other pollinators. A white-flowered variety is also available, offering a softer, more ethereal look.

Borage grows best in full sun, though it tolerates light afternoon shade in hotter climates. It’s wonderfully unfussy about soil, performing well in average to poor, well-drained ground with a slightly alkaline to neutral pH of around 6.0 to 7.0. Rich soil tends to produce lush foliage at the expense of flowers, so there’s no need to amend heavily. It’s drought tolerant once established and is considered deer resistant, as the prickly, hairy texture of the leaves and stems is unappealing to browsers.

What truly sets borage apart is that it’s entirely edible. The flowers carry a mild cucumber-like flavor and are stunning frozen into ice cubes, scattered over salads, or used to garnish cocktails and desserts. Young leaves can be added to salads or cooked as a pot herb, and the plant has long been associated with culinary and folk medicinal traditions throughout Europe. In the landscape, borage works beautifully as a cottage garden filler, a kitchen garden companion plant, or a bold addition to pollinator gardens. It’s one of the best companion plants for tomatoes, squash, and strawberries, reputedly deterring certain pests and attracting beneficial insects.

Planting borage

Direct sowing is almost always the best approach with borage, as it develops a taproot early and doesn’t transplant especially well. Sow seeds directly in the garden after the last frost date, pressing them about a quarter to half inch into the soil. Borage germinates quickly, usually within 7 to 14 days, and grows with impressive speed. You can also start seeds indoors in biodegradable pots 3 to 4 weeks before transplanting, which minimizes root disturbance. Space plants or thin seedlings to about 12 inches apart to allow for their bushy spread. For a continuous supply of flowers throughout the season, make successive sowings every few weeks from spring through early summer.

Watering

Borage is refreshingly low-maintenance when it comes to water. It prefers consistent moisture while getting established but becomes quite drought tolerant once it’s settled in. Water young plants regularly, aiming to keep the soil evenly moist but never waterlogged. Once the plant is several inches tall, you can ease off and water only during extended dry spells. Overwatering is a more common problem than underwatering, and soggy soil can lead to root rot. In average garden conditions with normal rainfall, established borage often needs no supplemental watering at all.

Fertilizing

Less is more when it comes to fertilizing borage. Because it performs well in poor soil and prioritizes flowering when nutrients are limited, feeding it generously can actually work against you by producing a lot of foliage with fewer blooms. If your soil is very poor or sandy, a single light application of a balanced, slow-release fertilizer at planting time is sufficient. In most garden soils, no fertilizing is needed at all. Avoid high-nitrogen fertilizers, which push leafy growth at the expense of the flowers you’re growing borage for in the first place.

Pruning and deadheading

Borage doesn’t require much pruning, but a little attention goes a long way toward keeping it productive and tidy. Deadhead spent flowers regularly to encourage the plant to keep blooming rather than putting energy into seed production. If the plant becomes leggy or floppy mid-season, which can happen in humid or overly fertile conditions, you can cut it back by about one-third to encourage fresh, compact new growth. Staking isn’t usually necessary, but if you’re growing borage in a windy spot or it’s sprawling more than you’d like, a simple ring support placed early in the season can help keep it upright.

Harvesting flowers and leaves

Harvest borage flowers in the morning after the dew has dried, when the blooms are fully open and at their freshest. They’re best used the same day, as they wilt quickly after picking, though you can float them in ice water for a few hours to keep them perky. Pinching flowers regularly not only gives you a steady harvest but also prolongs the plant’s overall blooming period. Young leaves are most palatable when harvested early in the season before the plant matures, as older leaves become more coarse and intensely hairy. Always harvest leaves from the outer portions of the plant to allow the center to keep growing.

Self-seeding and naturalizing

One of borage’s most useful traits is its tendency to self-seed generously. Once you’ve grown it for a season, you’ll likely find new seedlings appearing in and around the same spot the following spring. If you’d like to encourage this, simply allow a few flower heads to mature and drop their seeds at the end of the season. If you’d rather control where it spreads, deadhead diligently before seeds ripen. The self-sown seedlings are often more vigorous than transplanted starts and tend to establish quickly. Because borage produces a taproot, these volunteer plants are generally best left where they sprout rather than moved.

Companion planting

Borage has one of the strongest reputations of any plant in the companion planting world. It’s widely grown alongside tomatoes, where it’s said to repel tomato hornworms and improve the flavor of the fruit. It’s also a popular companion for strawberries, squash, and cucumbers. Whether or not all the folklore holds up to scrutiny, the fact that borage draws in enormous numbers of bees and other pollinators is well established, and that alone makes it a genuinely valuable presence in any vegetable or fruit garden. Its flowers also attract predatory insects like parasitic wasps that prey on common garden pests.

Pests and diseases

Borage is a tough, largely trouble-free plant. Aphids occasionally cluster on new growth and flower buds, but they’re rarely present in numbers large enough to cause serious harm. A strong spray of water from the hose is usually all it takes to knock them back. Powdery mildew can appear on older leaves late in the season, particularly in humid conditions or when air circulation is poor. Because borage typically blooms heavily before mildew becomes a real problem, this is more of a cosmetic nuisance than a genuine threat. Removing affected leaves and avoiding overhead watering helps minimize it. Root rot can occur in poorly drained soil but is easily prevented by choosing a well-drained site from the start.

End-of-season care

Borage is a true annual, so it won’t survive frost. Once the plant is killed by cold, you can pull it and compost it or simply cut it back to the ground. If you want it to return next year through self-seeding, leave the spent flower heads in place for several weeks before the first frost so the seeds have time to mature and fall. Mark the area where it grew so you don’t accidentally disturb the seedlings that emerge the following spring. In mild-winter climates where frost is light or rare, borage may linger through the cool season and reseed in fall for an early spring show.

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Frequently asked questions

Is borage a perennial or an annual? Borage is an annual, completing its entire life cycle in one growing season. However, it self-seeds so freely that it often returns to the same spot year after year, giving it a perennial quality in many gardens.

Can you eat borage flowers? Yes, borage flowers are entirely edible and have a mild, refreshing cucumber flavor. They’re popular as a garnish for salads, drinks, and desserts, and they’re especially striking when frozen into ice cubes for summer beverages.

Does borage spread aggressively? Borage spreads by self-seeding and can produce quite a few volunteer seedlings if allowed to go to seed. It’s not considered invasive, and the seedlings are easy to pull if they pop up where you don’t want them. Deadheading before seeds ripen keeps the spread in check.

Why are my borage plants leggy and falling over? Legginess is usually caused by too much shade, overly rich soil, or warm, humid weather. Try cutting the plant back by a third to encourage bushier regrowth. In future seasons, choose a full-sun location and avoid amending the soil heavily before planting.

When should I plant borage seeds? Direct sow borage seeds outdoors after the last frost date in spring. In mild climates, you can also sow in late summer or early fall for cool-season growth. For an early start, sow seeds indoors in biodegradable pots 3 to 4 weeks before your last frost date.

Does borage attract pollinators? Borage is one of the most bee-friendly plants you can grow. Its flowers produce nectar continuously throughout the day and are visited constantly by honeybees, bumblebees, and a wide range of native bees and beneficial insects.

Is borage deer resistant? Yes, borage is generally considered deer resistant. The coarse, bristly hair covering its leaves and stems is unappealing to deer, and the plant is rarely browsed.

Can I grow borage in a container? Borage can be grown in a large container, though it tends to perform best in the ground where its taproot has room to develop freely. If you’re growing it in a pot, choose a deep container at least 12 inches wide and deep, use a well-draining potting mix, and water more frequently than you would in-ground plants, since containers dry out faster.