Herb · Boraginaceae
Borage
Borago officinalis
Plant it a single season and the blue star flowers and bees return on their own.
Full sun
Every 3–7 days
50–86°F · 10–30°C
55–75 days
Overview
Borage is the relaxed herb whose bright blue, star-shaped flowers keep bees circling, and it brings an effortless cottage mood to a sunny border or a kitchen plot near the back door. A fast-growing annual of the borage family, it asks only for full sun and shrugs off the poor, dry ground that defeats fussier choices. Give it one season and it tends to make itself at home for the long run.
The young leaves and open blooms offer a clean, cucumber-like taste that finds its way into summer drinks, a fresh salad, and a candied flourish on a dessert plate. Stiff bristly hairs cover the whole plant, so a pair of gloves belongs in the harvest basket. Picked young and tender, both leaves and flowers reward the trip outdoors.
What borage offers in easy charm it can reclaim through its reach. Left to flower and shed its seed, it reseeds itself freely and reappears around the garden the next year, so a light routine of deadheading keeps it framing the spaces you intend.
Care
The short version: give it full sun and well-drained soil that leans toward the lean and dry. Water to settle it into its spot, then ease back once it has rooted, keep feeding to a minimum, and deadhead the flowers to temper its keen self-seeding.
Light
Borage prefers full sun to settle into a stocky shape and flower with conviction, though it accepts partial shade when needed. Starved of light, it stretches into a tall, floppy form that leans and gives way.
Water
Water often enough to hold the soil evenly moist while the plant finds its feet. From there it grows fairly drought-tolerant and manages lean, dry ground, so ease back and simply steer clear of waterlogging.
Soil
Ordinary well-drained garden soil suits it well, and it even copes with poor, dry corners that defeat other herbs. A pH of 6.0 to 7.0 sits in the sweet spot, though borage stays unbothered by anything beyond good drainage.
Temperature
It thrives across a generous range, roughly 50°F to 86°F (10°C to 30°C). Frost closes the book on an annual borage, so let the cold pass before you sow.
Humidity
The everyday outdoor air of 40% to 60% is all it requires. Good airflow matters more than any humidity figure, since crowded, stagnant air opens the door to powdery mildew on the leaves.
Feeding
Borage is a light feeder that wants very little. A handful of compost or a balanced fertilizer at planting covers it on poor soils, while rich ground only encourages weak, floppy stems.
Pruning
Pinch the growing tips early for a fuller, sturdier plant, and deadhead spent flowers to keep the blooms arriving and rein in the heavy self-seeding. Trim back any leggy or flopping growth to refresh the foliage.
Repotting
Borage is not truly suited to a pot. Its taproot resents being moved, so it goes straight into the ground where it grows rather than being potted up or repotted.
Size & spacing
Plants stand 18 to 35 inches (45 to 90 cm) tall and spread 12 to 24 inches (30 to 60 cm) across. Allow each one that breathing room so air can flow and mildew stays at bay.
When to plant
Borage takes its cue from warmth and would rather not be relocated, so the season opens once the frost has gone. Sow the seed straight into warm spring soil, watch the blue flowers unfold from early summer, and gather young leaves and blooms all the way to fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Generally not recommended; borage has a taproot and resents transplanting. If started indoors, sow in deep pots 3-4 weeks before last frost.
- Plant: Direct-sow after the last spring frost once soil has warmed
- Harvest: Blue star-shaped flowers appear from early summer through fall; harvest young, tender leaves and open flowers as needed
Hardiness
USDA hardiness zones: 2–11
Temperature: down to -46°C
Troubleshooting
Borage carries on through most setbacks, and the handful it does face stay mild and simple to read. Keep an eye on the fresh growth and the shaded lower leaves for the earliest hints. Match what you notice below and respond before it builds.
Young volunteers turning up across the beds
Borage is a generous self-seeder, and a single plant allowed to flower and shed its seed returns as a small crowd the following spring. Clip the spent blooms before the seed ripens, and lift or hoe the seedlings while they are still small and easy to move. Cutting plants back ahead of the seed drop keeps the wandering in bounds.
Fix:
- Deadhead spent flowers before seed sets to limit reseeding
- Pull or hoe unwanted volunteer seedlings while young
- Harvest or cut plants before mature seed drops
Tender new growth dressed with a colony that doesn't belong
When the soft tips and leaf backs collect small clustered insects and a sticky sheen, you are looking at aphids settling in. A firm rinse from the hose clears most of them, and a borage patch tends to invite ladybugs and lacewings that handle the rest, so a modest gathering seldom calls for fuss. Save insecticidal soap for the rare moment a colony truly takes over.
Fix:
- Spray plants with a strong jet of water to dislodge aphids
- Tolerate minor populations, as borage attracts beneficial predators such as ladybugs and lacewings
- Use insecticidal soap only if infestation is severe
A pale dusting settling over the upper foliage
That chalky bloom across the top of the leaves is powdery mildew, a fungus that arrives on warm afternoons and cool, damp evenings, most often where plants sit too close together. Open up the planting so air can pass through, clear away the worst leaves, and keep watering at the base. It tends to surface late in the season and seldom proves fatal.
Fix:
- Improve air circulation by thinning crowded plants
- Remove and discard heavily affected foliage
- Avoid overhead watering
A tall plant losing its footing after a storm
Quick to grow and built around hollow stems, borage that has been coaxed along with rich soil or shade turns leggy and brittle and tips over under its own weight. An early pinch at the tips builds a stockier, more branching shape, and a slim stake or a leaning neighbor lends quiet support. Full sun on lean ground keeps the form compact enough to hold itself upright.
Fix:
- Pinch tips early to promote bushier, sturdier growth
- Provide light staking or grow among supporting companion plants
- Site in full sun and avoid over-fertilizing
Toxicity
Borage occupies an unusual place in the garden: people enjoy its flowers and young leaves, yet the plant carries pyrrolizidine alkaloids that can harm the liver in quantity. Treat it as a garnish to be enjoyed in moderation, and keep horses, livestock, rabbits, and birds well clear of it, since these animals face far greater risk than a person taking the rare taste.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
An occasional nibble usually amounts to little more than mild stomach upset, yet the pyrrolizidine alkaloids in the leaves settle into the liver over time. Discourage a cat from returning to graze the plant again and again.
Dogs Mild
A dog that samples a single leaf out of curiosity may feel briefly queasy and nothing worse, though repeated servings raise a genuine liver risk as the alkaloids gather. Guide dogs away from the foliage.
Horses Toxic
Horses prove especially sensitive to pyrrolizidine alkaloids, which scar the liver as the dose mounts. Because the harm advances quietly, weight loss, a lackluster coat, and odd behavior may appear well after the grazing. Keep borage clear of pasture and hay.
Rabbits Toxic
Coarse and laden with alkaloids, the leaves do a rabbit no favors, and every meal adds to the load carried by the liver. Leave borage off the forage list entirely.
Livestock Toxic
Cattle, sheep, and goats that browse borage take on pyrrolizidine alkaloids that wear at the liver across weeks and months. Dullness, weight loss, and poor condition signal the slow damage at work. Keep it well away from grazing ground.
Birds Toxic
Those same liver-toxic alkaloids make borage foliage a poor fit for poultry and pet birds alike, so keep it off the menu.
People Edible in moderation
The young leaves and blue flowers are a long-loved kitchen herb, pleasant to eat now and again for their cool, cucumber note. The caveat is the pyrrolizidine alkaloids, which can tax the liver under heavy or steady use, so let borage play the part of a garnish rather than a daily green.
Wear gloves or long sleeves when handling or harvesting, as the stiff bristly hairs can mildly irritate skin. Consume flowers and young leaves only in moderation due to pyrrolizidine alkaloid content.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Borage offers only a small choice of forms, set apart chiefly by the color of their flowers. Both grow and taste alike.
Borago officinalis (common borage)
The familiar species brings the bright blue, star-shaped flowers and the bristly, cucumber-flavored leaves that come to mind first whenever borage is mentioned.
Borago officinalis 'Alba' (white borage)
This form swaps the blue blooms for crisp white ones and behaves exactly like the parent in all other respects.
Companions
Borage earns its place beside fruiting crops by pulling in bees and other pollinators that lift their yields.
Plant near
Tomato: Borage attracts pollinators and beneficial insects and is a traditional companion planted near tomatoes
Strawberry: Borage is a classic companion for strawberries, drawing pollinators that improve fruit set
Squash: Its abundant blue flowers attract bees and other pollinators that benefit pollination of squash and other cucurbits
How to propagate
Borage very nearly plants itself, which leaves seed as the one method that counts and the only one you will ever reach for.
SeedEasy
Direct-sow outdoors after the last spring frost once the soil has warmed · Seeds typically germinate in 1-2 weeks and plants establish within several weeks
Set borage seed directly into the spot you have chosen for it, since the deep taproot dislikes being lifted and moved. Hold off until the last spring frost has passed and the soil has warmed, after which the seedlings appear in 1 to 2 weeks and broaden over the following few weeks. Once it has taken hold, it carries on sowing itself for years.
Myths
Borage is a completely safe culinary herb you can eat in any amount.
Both leaves and stems hold pyrrolizidine alkaloids capable of harming the liver when taken in quantity or over a long span. The flowers and young leaves serve well as an occasional garnish, so treat borage as a flavoring, not a staple green.
Planting borage once is enough because it's only an annual.
True, it fades each year, yet it scatters so much seed that it comes back on its own season after season. Allowed to set seed, one plant can colonize a whole bed and slip into weediness.