How to Grow Borage from Seed for Bees & Edible Flowers

Last updated: August 3, 2026

Growing Borage for Bees & Edible Flowers

Borage (Borago officinalis) is one of the few plants that earns a spot in the flower bed, the herb garden, and the vegetable patch all at once. Direct sow it after your last frost and within about eight weeks you have a sturdy, branching plant hung with clusters of brilliant five-pointed blue star flowers over silvery, bristled leaves. The flowers and young leaves taste of fresh cucumber, the blooms pull in bees from morning to dusk, and a plant or two dotted through the vegetable beds feeds the pollinators and predatory insects your fruiting crops depend on.

Borage is also refreshingly low-maintenance. It asks nothing more than sun and average soil, shrugs off drought once established, and self-seeds so reliably that a single sowing usually means borage every year after. That combination of beauty, usefulness, and near-total independence is why it has been a cottage-garden staple for centuries. This guide covers the full journey: choosing a variety, sowing, climate and timing, season-long care, keeping its spread in check, harvesting, cooking, who should not eat it, and saving seed.

Borage Varieties

Nearly all borage grown from seed is common blue borage — the classic star-flowered annual. A few named forms add colour variety, and one close relative offers a perennial habit, but they all grow the same way.

For almost every gardener, common blue borage is the one to grow — it is the strongest bee plant, the best-known edible flower, and the classic companion crop. The white ‘Alba’ and variegated forms are grown mainly for looks and behave identically in the garden.

Creeping borage is a different species entirely, and a much narrower one. Kew’s Borago pygmaea record gives its native range as Corsica, Sardinia and the Italian island of Capraia, and describes it as a biennial or perennial rather than an annual. It suits a rockery or a dry bank rather than a vegetable bed, and it is far less useful in the kitchen. If you want borage for bees, salads, or a companion crop, grow the common blue form.

Before You Grow Borage

Borage wants full sun and average, well-drained soil that runs dry to medium rather than wet. Missouri Botanical Garden’s Plant Finder record gives it Zones 2 to 11 and rates it for dry to medium moisture, tolerant of part shade, poor soil and drought. Read that zone span for what it is: borage is grown as an annual everywhere, so the range says it will finish a season almost anywhere in North America, not that it survives winter. What it will not tolerate is heavy, soggy ground, where it flops and mildews.

Give it room. A mature plant reaches 60–90 cm (24–36 in) tall and sprawls about half that wide. University of Maryland Extension’s borage fact sheet, cited below, puts plants 30 cm (12 in) apart in rows 45 cm (18 in) apart — close enough that neighbours prop each other up, open enough that air moves through the foliage.

Treat borage as a direct-sow crop, but know that the sources split on how firm that rule is. Maryland calls it difficult to transplant and UC Marin’s growers say flatly that it does not transplant well; Missouri Botanical Garden and Illinois Extension both say seed may be started indoors or sown straight outside. Nobody publishes a mechanism for the difficulty — the taproot explanation repeated across the internet is inference, not a finding. Direct sowing is the low-risk default; if you must start early, use deep individual pots and move plants out young with the root ball intact. Site it where its self-seeding is welcome and where its bee-drawing power does the most good, so a border beside the tomato patch is an ideal home if you are already following how to grow tomatoes.

🌱 How to Grow Borage Seeds

Direct Sowing Borage Seeds Outdoors

Sow borage seeds about 1 cm (½ in) deep once your last frost has passed, and cover them completely. Depth is not optional with this crop: light inhibits borage germination, so surface-scattered seed sprouts thinly and erratically while buried seed comes up evenly across the row. Ontario’s agriculture ministry sows deeper still for field crops — its specialty crop profile gives 1.25–2.5 cm (½–1 in) depending on soil moisture, and an optimal soil temperature at planting above 10°C (50°F). Go to the deeper end of that range in dry spring soil, the shallower end in a moist, well-worked bed.

Sowings made into cold, wet spring soil are the single most common reason a borage packet disappoints. If your beds stay saturated into late spring, wait an extra week rather than sowing into mud — borage catches up fast and a warm-soil sowing overtakes an early one within a fortnight.

Germinating Borage Seeds

Borage germinates over a remarkably wide temperature band. Ghaderi and colleagues’ cardinal-temperature study in the Asian Journal of Plant Sciences measured a base of 5°C (41°F), an optimum of 29.9°C (86°F) and a ceiling of 39.9°C (104°F). That low base is exactly why self-sown volunteers appear so early in spring, and why fall sowings work in mild-winter regions; the ceiling is why midsummer sowings fail in the desert Southwest.

Emergence is where honest sourcing runs out. No extension service, agriculture ministry or botanical institution publishes a days-to-emergence figure for borage — they publish depths, dates and spacings instead. In practice a warm-soil sowing breaks ground inside a fortnight and a cold one takes noticeably longer, but that is an observation, not a specification, and you should plan around soil temperature rather than a calendar. Seedlings emerge with two broad, slightly hairy cotyledons and put on size quickly once the first true leaves appear. Do not thin until they are 8–10 cm (3–4 in) tall.

Light is the other half of the equation, and it is the reason shallow sowings disappoint. Theimer and Schuster’s 1978 light-inhibition paper in Zeitschrift für Pflanzenphysiologie is the only study of the effect, and it is the reason the instruction is cover the seed completely rather than press it into the surface. Seed left sitting on top or barely dusted over germinates thinly no matter how warm and moist the bed is. Firm the soil lightly over it and let darkness do its job.

Succession Sowing Borage

Sow a short fresh row every four weeks through early summer if you want an unbroken supply of tender leaves, since individual plants coarsen as they age. Maryland and Illinois extension both give the same interval, and Maryland puts a number on it: three sowings at four-week spacing carry a whole season. After the first year this becomes largely unnecessary, because volunteer seedlings arrive in waves on their own and can simply be thinned to where you want them.

Growing Borage Across North American Climates

Borage grows almost anywhere in North America, but the timing and the challenge shift by region. Match your approach to the climate you garden in.

Planting Borage by Zone

Borage is grown as an annual everywhere in North America — it dies at hard frost and returns from self-sown seed. Use your zone to time the first sowing. No agency publishes a zone-by-zone borage calendar, so the table below is built from the two figures that are published — the 10°C (50°F) soil-temperature floor and the 39.9°C (104°F) germination ceiling — set against regional frost dates.

Caring for Borage Through the Season

Once it is up and thinned, borage is close to self-sufficient. Season-long care comes down to a little water early on, very light feeding at most, occasional support, keeping its enthusiastic self-seeding within bounds, and handling those bristly leaves sensibly.

Watering Borage

Water borage steadily only while it is establishing, then taper off — established plants want water only in prolonged dry spells. NC State Extension’s plant toolbox profile tags borage drought-tolerant and suits it to occasionally dry ground, and Illinois says the same once it is established. Keep the soil evenly moist until the seedlings are up and growing away, then switch to deep, infrequent soakings during real drought. Soggy soil causes far more trouble than dry soil here, pushing the soft growth that mildew colonises and inviting rot at the stem base.

Fertilizing Borage

Feed borage sparingly if at all — and here the published advice splits. Missouri Botanical Garden rates borage as tolerating poor soil outright, while UC Marin’s borage plant guide recommends a balanced organic fertilizer monthly at half the label rate. Nobody publishes a borage-specific trial showing that richer ground costs you flowers, so treat the popular “feed it and you get leaves instead of blooms” line as untested. In an average bed, one light dose of compost worked in at sowing carries the season; in exhausted ground, the half-rate monthly feed is the sourced option.

Staking Borage

Stake borage before the first flowers open, not after it has already gone over. Illinois Extension describes the plant as brittle and easily damaged by wind, and suggests staking on that basis. A top-heavy plant in an exposed or over-rich site will flatten in the first summer storm — after which the flowering stems that mattered are already kinked.

Controlling Borage Self-Seeding

Borage self-seeds prolifically, and the fix is to deadhead before seed sets — the single most effective control, and it pushes the plant to bloom longer as a bonus. Two things are worth separating here, because the sources say different things about them. On the legal and ecological question, the Canadian Food Inspection Agency’s borage biology document states that borage is not listed in Canada’s Weed Seeds Order, 2016 and is not reported as a problematic weed of managed ecosystems, or as invasive of natural ones, anywhere in the world. On the garden question, UC Marin’s growers are blunter: borage is a prolific self-seeder that may become invasive in a bed, and you will likely always have some once you plant it. Both statements are true at once — borage is a nuisance in a border, not a threat to a woodland.

Volunteers are also a resource rather than a chore. UC Agriculture and Natural Resources’ Magical Marvelous Borage notes that self-sown borage seedlings are easy to dig and move while small — so the ones that come up in the wrong place become free plants for the far end of the garden. Plan for more than one season of them: CFIA records volunteers appearing at least two years after a borage crop, and notes that no study has measured how long the seed persists in soil.

Handling Borage’s Bristly Foliage

The stiff white hairs on borage stems and leaves are more than a texture quirk — they are the reason harvesting a mature plant bare-handed is unpleasant. Young leaves are soft enough to pick and eat straight off the plant, but by mid-season the bristles on stems and older foliage stiffen noticeably.

Wear gloves for any real handling once the plant is knee-high. University of Illinois Extension’s borage herb profile warns that the harsh hairs may cause skin irritation in some people, and NC State separately flags contact dermatitis, so wear gloves and long sleeves when you cut a plant back, pull it at season’s end, or chop foliage for mulch — and rinse your forearms afterwards if you are prone to contact reactions.

Borage Pests & Diseases

Borage is one of the most trouble-free plants you can grow, and its own flowers summon the predators that clean up most pests. Missouri Botanical Garden and NC State both record no serious insect or disease problems beyond occasional powdery mildew. The fullest list of what has been recorded on the crop comes from Ontario’s agriculture ministry, whose specialty crop profile names aphids, Japanese beetle, painted lady caterpillars, powdery mildew, white mould and bird damage — and that list, not the generic herb-pest roster, is what the table below follows.

🤝 Best Companion Plants for Borage

Borage earns its place beside fruiting crops by feeding insects, not by repelling anything. University of Delaware Extension’s companion planting fact sheet draws the line worth keeping in mind — most traditional pairing claims rest on folklore, while the benefit that does hold up is diversity that attracts and sustains beneficial insects — and it names borage among the herbs shown to do exactly that. The table sets out the pairings and what each one rests on; the sections below go deeper on the three that get asked about most.

Planting Borage With Strawberries

Strawberries are the one borage pairing that has been put through a field trial, and the honest summary is weaker than the version circulating online. Nathan Hecht’s 2019 flower-strip thesis at the University of Minnesota planted borage strips at one end of day-neutral strawberry plots and measured yield by distance over two seasons. Average berry weight and berry number were lowest in the plots farthest from the borage in both years — but distance did not have a statistically significant effect, and the clearest decline showed up in a single cultivar, ‘Evie-2’. Treat it as a promising trend, not a rule.

Two practical points survive that caveat. Plant borage in among the strawberry rows rather than in a tidy patch at one end, since the trend runs the right way and costs you nothing. And do not assume the honeybees are doing the work: the trial’s main strawberry visitors were hoverflies, anthomyiid flies and small native bees, so what you want is a long, uninterrupted bloom that feeds small insects, which is exactly what borage provides.

Planting Borage With Tomatoes

Borage beside tomatoes works through nectar, not repellence, and the distinction changes where you put it. The wasp that matters is Cotesia congregata, whose larvae kill tomato hornworm. NC State Extension’s parasitoid fact sheet explains that females find hosts by the smell of caterpillar-damaged foliage — the tomato plant recruits them, borage does not — but also that the adults feed at flowers. Borage is the nectar station that keeps those adults in your garden long enough to find the hornworms. So plant it within a few metres of the tomatoes, flowering before the hornworms arrive, rather than expecting it to drive anything away.

Planting Borage With Squash

The squash pairing is reasonable and untested, and it is worth knowing which. No study has measured borage next to cucurbits. Working against the idea: USDA’s Squash Bee Overview describes Peponapis and Xenoglossa as strict Cucurbita pollen specialists and often the dominant pollinators of the crop — insects borage cannot recruit, and where they are abundant they pollinate the flowers before honeybees are even flying. Working for it: many gardens have few or no squash bees, and there generalist bumblebees and honeybees do the pollinating, which borage does support. Plant it beside the hills if you rarely see squash bees; expect less from it if you do.

Stacking Borage With Other Nectar Plants

Stack borage with other nectar plants and the effect compounds, because a bed that flowers continuously holds its pollinator population instead of attracting and losing it. Borage covers midsummer to frost; pair it with a perennial that opens earlier and you have coverage across the whole season — how to grow bee balm covers the obvious partner.

Harvesting Borage

Harvesting Borage Flowers

Pick borage flowers the day you use them — they wilt within hours and do not store. Snip or pinch individual blue stars off as they open, taking the whole flower and leaving the hairy green calyx behind, which is easiest done by pinching the black centre cone and pulling gently. A single established plant carries hundreds of blooms over a season, so daily picking barely dents it.

Harvesting Borage Leaves

Take borage leaves young — ideally before they pass about 10 cm (4 in) — while the hairs are still soft and the cucumber flavour is clean. Pinch them from the growing tips rather than stripping the base of the plant, which keeps the crown intact and pushes fresh growth. Use them the same day: Maryland extension’s borage fact sheet notes that the leaves are used fresh and seldom dried, because drying strips the flavour out entirely and leaves nothing but bristle.

Keeping Borage Flowers Fresh

Clean borage flowers by swishing, never rinsing. Fill a bowl with cool water, drop the blooms in, move them gently with your fingers, then lift them out and lay them in a single layer on a towel — a tap running directly onto a borage petal bruises it instantly. For anything longer than a few hours, freeze the flowers whole into ice cubes or candy them in beaten egg white and superfine sugar; both hold the colour far better than refrigeration does.

One caution on the candying, because candied flowers usually end up on a cake a child eats: the classic method leaves the egg white raw. USDA’s Food Safety and Inspection Service is unambiguous in Shell Eggs from Farm to Table that everyone is advised against eating raw or undercooked egg white, and that recipes calling for raw egg should use pasteurized egg or egg products. Use pasteurized egg white or reconstituted meringue powder and the result is identical.

🍽️ Cooking with Borage

Borage tastes clean and cool, like fresh cucumber with a faint honey sweetness — which is exactly why it became a summer kitchen staple long before it was a pollinator plant. Colorado State University Extension’s edible flowers fact sheet lists borage among the flowers safe to garnish with or candy, and attaches three cautions worth carrying: use only unsprayed material, be certain of your identification, and try a small quantity first. The flowers are the showpiece and the young leaves are the workhorse, and they suit different jobs.

Borage is a bulk vegetable somewhere, though, and that somewhere is Spain. The FAO’s survey of neglected crops, cited in the history section below, records borage grown as a field vegetable in the Ebro valley — Zaragoza, Logroño and Navarra — with the leaves cooked in soups and stews, battered and fried, or made into fritters in Majorca. For a North American garden, though, treat borage as a garnish and a flavouring rather than a bulk green. Quantity is the one place where it has a real limit, and it comes down to plant chemistry rather than taste.

Is Borage Safe to Eat?

Borage is a legal food that regulators cap rather than ban, and the compounds behind the caps are unsaturated pyrrolizidine alkaloids — hepatotoxic, and a concern for cumulative dose rather than for any single meal. That makes the answer depend almost entirely on how you are eating it, so start with the pattern rather than the plant.

Pyrrolizidine Alkaloids in Borage

The current binding numbers are European, and they name borage directly. Regulation (EU) 2020/2040 introduced maximum pyrrolizidine alkaloid levels that now sit in the consolidated contaminants regulation: 750 µg/kg for fresh or frozen borage leaves sold to the final consumer, and 1,000 µg/kg for dried borage, measured as the sum of 21 named alkaloids. Read those the right way round. They are limits written for a vegetable that is lawfully on sale — the regulatory position is that borage is food worth capping, not food worth banning.

Two figures quoted alongside them need a date stamp. The “no more than 1 microgram a day” limit repeated across herbal references comes from a 1992 directive of the German Federal Health Agency — a body dissolved in 1994 — and that same directive set a stricter 0.1 µg for use beyond six weeks, the half that usually gets dropped in the retelling. Germany’s current food-safety institute, the BfR, now declines to publish a safe intake level at all, on the grounds that none can be derived for a genotoxic carcinogen; it works from a margin of exposure instead. Memorial Sloan Kettering’s monograph carries the practical numbers for the oil: it should be certified to no more than 0.5–1 µg of unsaturated alkaloids per gram, and 1–2 g a day of an uncertified oil can push intake toward 10 µg.

Cooking is not a way around any of this. The European Food Safety Authority’s pyrrolizidine alkaloid assessment concluded that exposure is a possible long-term concern for frequent and high consumers of tea and herbal infusions because of potential carcinogenicity, and separately flagged supplements based on alkaloid-producing plants for short-term toxicity. Heat is unreliable as a defence: the evidence is contested, and what heating demonstrably does is convert the N-oxide forms into free-base alkaloids rather than remove them, leaving the total load roughly where it started. Blanching large leaves for a pasta filling changes the texture, not the chemistry.

Who Should Avoid Borage

Anyone pregnant or breastfeeding should avoid medicinal and concentrated borage entirely — oil, capsules and teas alike. Memorial Sloan Kettering’s borage monograph records teratogenic effects for borage oil and notes that its prostaglandin E agonist action may bring on premature labour. The US National Library of Medicine’s lactation database takes the same line from the other direction, advising that borage plant parts such as leaves be avoided while breastfeeding and that only certified alkaloid-free oil be considered.

Infants are a separate case with a separate mechanism, and it is the one most often reported wrongly. Multiple cases of methemoglobinemia in Spain were clearly linked to babies fed borage purée — but the cause is borage’s high nitrate content, the same hazard that makes spinach and beetroot purées a concern in infant feeding, not the pyrrolizidine alkaloids. The rule that follows is narrower and firmer than a general alkaloid warning would give you: no borage purée for babies, and a low-alkaloid product does not change it.

Is Borage Toxic to Dogs, Cats & Horses?

Yes, and this is the one place a lot of garden writing gets borage backwards. Borage carries an affirmative entry on the ASPCA’s toxic-plant database, listed as toxic to dogs, cats and horses, with vomiting, diarrhea and dermatitis as the reported signs. The ASPCA attributes that to tannins and mucilage rather than to the alkaloids, so it is a separate finding from everything above, not a restatement of it. A single curious nibble on a border plant is not an emergency, but borage is not a plant for a run where a dog grazes, and it is not something to hand to an animal deliberately. Call your vet if a pet eats a quantity of it.

Livestock sit in a thinner evidence position. Borago is not among the genera the Merck Veterinary Manual names as causes of pyrrolizidine alkaloidosis, and I found no documented case of borage poisoning in stock — an absence of evidence rather than evidence of safety. Since cattle and horses are the species most susceptible to alkaloid liver damage in general, and since the damage is cumulative from repeated small doses, the prudent line is the same one: fine as a field-margin bee plant, not something to graze or cut for feed.

Borage as a Pollinator & Soil-Building Plant

Growing Borage as Bee Forage

Borage is a good bee plant, and it is worth being precise about why, because the usual claim overshoots. Stawiarz and colleagues’ 2020 forage-value study in the Journal of Apicultural Science measured a Polish borage crop across three seasons and put its nectar sugar yield at 52.1 kg per hectare over an eight-week bloom, with bees making 73% of insect visits and insect pollination lifting borage’s own fruit set by 43.3%. The same paper is equally clear that this is well short of winter rape at 90–120 kg per hectare and white mustard at 71.2, and it says why: borage flowers less densely than either. Its own verdict is “a good value crop” — not the best bee plant you can grow.

What borage does have going for it in a garden is breadth and duration rather than raw output. Honeybees, bumblebees and small solitary bees all worked the flowers in that trial, and flies did too — a wide visitor list matters more in a mixed garden than a high per-hectare figure does. It has long been recommended in beekeeping literature as a nectar plant to grow near apiaries, and a patch beside a pollinator planting extends the whole bed’s useful season, which is what bee gardens and pollinator flower planting covers in full.

Using Borage Foliage as Mulch

Borage makes an excellent chop-and-drop mulch, and it is worth separating what it does from what it is credited with. Cut plants at the base with shears two or three times a season, chop the stems into rough lengths, and leave them where they fall around fruiting crops. Soft, high-moisture growth like this breaks down fast and returns whatever it contains to the surface layer — that much is straightforward residue chemistry, and it is why a borage mulch disappears in a fraction of the time a woody one takes. Gloves on; the stems are at their bristliest by the time they are worth cutting.

The claim to drop is that borage’s taproot mines potassium and calcium from the subsoil. Borage appears on every permaculture “dynamic accumulator” list going, but the concept has only ever been field-tested once, in a SARE-funded project whose dynamic accumulator field trials notes that the term has existed only in informal on-farm research and gardening books rather than in the peer-reviewed literature. That project tested six species — dandelion, lambsquarters, red clover, redroot amaranth, Russian comfrey and stinging nettle — and only two cleared the threshold. Borage was not among the six, and no tissue-analysis data for it exists at all. Use borage mulch for the fast-returning biomass, which is real; do not count on subsoil mineral mining, which nobody has measured.

One practical warning that follows from the self-seeding section: chop before the seed sets. Borage residue carried to a compost heap that never gets properly hot will seed every bed you spread that compost on, and CFIA records volunteers appearing at least two years after a crop. Cutting at first fade rather than at brown-head stage costs nothing and saves several seasons of weeding.

How to Save Borage Seeds

Watch the spent flowers and collect borage seed as the heads brown, because ripe seed drops within a day or two of ripening and the plant does not wait for you. Each faded bloom leaves four large black seeds just below it, which makes borage one of the easiest seeds in the garden to save — the challenge is timing, not technique.

There is no hybrid to worry about — borage is open-pollinated, and no F1 borage is sold — but “breeds true” is the wrong way to describe it. CFIA’s biology document records borage as primarily outcrossing and strongly dependent on bees for seed set, with flowers that are protandrous, shedding pollen before their own stigmas are receptive, which actively pushes pollen between plants. The literature has not settled whether borage is self-incompatible or self-compatible, and reports both. In practice that matters little if the whole neighbourhood grows the common blue form, since crossing blue with blue changes nothing you would see. It matters a great deal if you grow ‘Alba’ beside it and want white seed: bag two or three heads before the flowers open, because no isolation distance has ever been published for borage and any figure you find quoted is somebody’s guess.

Viability is the same story told honestly. Borage does not appear in the seed-viability tables published by Oregon State, Illinois Extension or Seed Savers Exchange, and CFIA states plainly that no study has evaluated how long borage seed persists. The 3–5 years repeated across seed catalogues is a working figure with no trial behind it — so store seed cool, dark and dry, label it with the year, and sprout ten seeds on damp paper towel before committing bed space to a batch more than a couple of years old. Ten minutes of testing beats an empty row.

🌍 A Short History of Borage

Borage has followed gardeners and beekeepers out of the Mediterranean and around the world, valued as food, medicine, and a symbol of courage.

Borage FAQ

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