Borage is one of the most enjoyable and easiest annuals to grow, and a must-have for anyone interested in natural, cottage, or potager style gardening. I have been growing borage for more years than I can remember, but I have only ever sown it once! This beautiful herb with its vibrant blue flowers repays me every year with an abundance of self-seeded borage plants to grow for another year. They are a clear signal that spring has arrived and summer is on its way.
Table of Contents
This year my allotment has been redesigned and cleared to incorporate a larger cut flower garden and I have yet to see a little borage baby. So, it is very apt that I get to share my experience, knowledge, and joy that comes with growing borage as I embark on sowing borage seeds for the second time.
Borage, also known as ‘starflower’, is an upright, bushy annual herb with attractive bright blue star-shaped flowers that stands out in any garden. Bees and butterflies love borage! Plants can be seen buzzing with bees all summer long. Predatory insects such as hoverflies and wasps also love to feast on the nectar of the borage flower making it a great companion plant in the vegetable garden.
The flowers of the borage plant have a subtle flavor of cucumber and make a perfect garnish for salads or candied decorations for cakes; but if you really want to impress your guests, try freezing flowers in ice cubes and adding them to cool summer drinks.
- Safer Brand Insect Killing SoapSouthern Ag Liquid Copper FungicideBonide Sulfur Plant Fungicide
Quick Care Guide
All About Borage
Borage, also commonly known as bugloss and starflower, is a member of the Boraginaceae family of plants along with comfrey, forget-me-not, and alkanet. Its botanical name is Borago officinalis, the term ‘officinalis’ indicating its use as a medicinal herb. Borage originates in the Mediterranean and has been used since ancient Greek and Roman times for a multitude of medicinal purposes including as an anti-inflammatory and a treatment for skin conditions such as dermatitis. Starflower oil produced from borage seeds is high in Gamma Lineolenic Acid, also called GLA, and is a common nutritional supplement for women of all ages. As will all medicines it is best to consult with a doctor to determine if they are right for you. Caution should also be used when consuming the vegetative form of the borage plant.
When conditions are right, borage can become a large vigorous plant reaching 24-36 inches tall (60-90cms) and 12-24 inches across (30-60cms). Its size and sprawling habit can bully neighboring plants, quickly outgrowing them and flattening them with its heavy, flower-laden branches. Provide plenty of space, cane supports, and trim to keep growth in check.
The flowers are bright purple-blue, sometimes pink, and often blue fading to pink with age. They have five-pointed petals in a star formation with the points of the green calyx behind the flower visible between each petal. Flowers grow densely in downward-facing clusters.
The stems and leaves are mid to dark green with fine silvery-white bristly hairs which can be an irritant to sensitive skin. Lower leaves are oval and large reaching 6 inches in length and grow abundantly from the base. Leaves on the main flowering stems are smaller and grow more sparsely. Seeds are black-brown, oblong, grooved on the sides with a little round hat on one end.
Seeds should germinate within 7-10 days in the warmth of early spring, with flowers appearing from June right through to early fall. When plants go to seed, they are finished for the year and begin to die. Borage is often referred to as invasive because of its rampant self-seeding habit. However, the seedlings are easy to identify and remove so it rarely becomes a major problem.
Borage leaves and flowers are edible and have a cucumber flavor. Both are best used fresh and younger leaves tend to be less hairy and more palatable. Bees that feed on borage flowers are also believed to produce some of the finest flavored honey.
Borage can be grown in large, deep containers filled with compost. Locate in a sheltered location, water often, and prune container-grown plants regularly to keep them tidy.
Here are some alternative cultivars to common borage. Borago officinalis ‘Alba’, a white-flowered variety, and Borago pygmaea, a perennial, low growing variety with small blue star-shaped flowers.
Planting
Borage is best sown directly outside in spring when all danger of frost has passed. Sowing direct help roots establish quickly providing a good ground anchor before they get too top-heavy and blow over. Borage also has a tap root that doesn’t transplant well.
For best results choose a full sun location to grow borage, although it can also tolerate partial shade. Sow borage seed in drills approximately 1 inch deep (2.5cm) and rows 12 inches apart (30cms), thinning emerging seedlings to 12 inches between plants (30cm). Soil can be amended with organic matter prior to planting to help with water retention, but it is not absolutely necessary. Borage grows well in drought conditions and poor soil. The extra organic matter and moisture retention simply help to establish strong roots and create a more stable plant. Support plants with stakes as they get taller for added wind protection.
Want to get a head start? Sow seeds indoors, one seed per cell, 3 to 4 weeks before the last frost date. Plant borage seedlings outside after all risk of frost is over and when plants are still quite young.
Growing borage in greenhouses and polytunnels is an excellent way to attract pollinators to vegetable crops grown under cover. Borage can also be grown in large, heavy containers filled with well-drained soil.
Care
Borage is an easy and enjoyable herb plant to grow in the garden. Follow our care guide below to keep those borage blooms coming all summer long.
Sun and Temperature
For strong plants and abundant flowers, grow borage in full sun to partial shade with at least 4-6 hours of sunlight per day. Suitable to grow in USDA zones 3 -10, borage is tolerant of high and cool temperatures but will die back with the onset of frost.
Water and Humidity
Although relatively drought-tolerant, borage will benefit from regular watering to develop healthy, strong upright plants. Water deeply with soaker hoses or by hand directing water at the soil. Provide lots of space between plants to improve air circulation and to reduce the risk of powdery mildew when humidity is high.
Soil
Borage grows best in well-drained soils spanning the whole gamut of sandy, loam, and clay. It will also grow well in a wide soil pH range including mildly acid, neutral, and mildly alkaline.
Fertilizing
Regular fertilizer is not necessary to grow borage. Soil amended at the start of the growing season will provide adequate nutrients.
Pruning
Borage can become a bit unruly with age, with sprawling stems lying on the ground and no real shape or profile. Keep mature plants trimmed to prevent them from becoming top heavy and flopping over. Regular deadheading will encourage more blooms and will reduce self-seeding. At the end of the season dig up and compost the entire plant (removing any seed heads first) to add lots of rich minerals and nutrients to future compost mulches.
Propagation
Propagate borage from seed either directly outside in the garden or in module cells for planting out later.
Sow seeds outside in drills approximately 1 inch deep (2.5cm) and rows 12 inches apart (30cms) after all risk of frost has passed. Thin emerging seedlings to 12 inches (30cm) between plants.
Start seeds indoors 3-4 weeks before the last frost date. Sow one seed per cell filled with general compost and plant out when all risk of frost has passed and borage plants are still quite young to minimize root disturbance.
Harvesting and Storing
Borage flowers, leaves, and seeds can be harvested and stored. Follow the tips below to help you enjoy borage at its freshest.
Harvesting
Harvest young leaves to add to salads or drinks; mature leaves tend to be tough and hairy. To harvest borage flowers, simply pull flowers from the plant as needed. Petals can be removed from the green calyx if desired but not necessary. Bright blue flowers are the freshest with the best cucumber flavor. Harvest seeds heads after flowering and store for sowing next year and sharing with friends.
Storing
Borage leaves and flowers are best used fresh but will store for a few days in the refrigerator gently wrapped in damp kitchen paper. Flowers can be frozen in ice cube trays and added to summer drinks or crystallized and used as cake decorations. Store seeds in paper envelopes in a cool, dry location.
Troubleshooting
Borage is easy to grow and usually trouble-free, but just in case, here are a few things to look out for.
Growing Problems
The main growing problem with borage is its untidy and sprawling appearance as it grows bigger. Stems are easily broken once laden with buds and flowers and tend to fall or blow over. To counteract this problem, trim plants regularly to keep them in shape and deadhead spent blooms. Provide plants with supports to keep them upright.
Pests
Aphids (Aphidoidea), in particular, feed on the sap of new growth. Treat biologically with predatory insects, such as ladybug larvae (cococinella septempunctata) and hoverflies by planting flowers that attract them into your garden. A quick spray of organic insecticidal soap will kill aphids as will squishing them with fingers.
Diseases
Borage can become infected with powdery mildew in hot, damp environments, developing a thick white fungal growth on leaves that inhibits photosynthesis and hinders growth. Foliage eventually turns yellow and dies. Maintain good garden hygiene removing infected foliage to prevent the disease from spreading and reinfection in subsequent years. Provide adequate sunlight and good air circulation. Treat affected plants with an organic fungicide such as copper fungicide, sulfur, or potassium bicarbonate, prior to or on first sight of disease.
Frequently Asked Questions
Q: Does borage come back every year?
A: Borage is an annual herb that germinates, flowers, and will go to seed within one season. However, if you have grown borage in your garden once, the likelihood is that it will self-sow and you will have lots of seedlings the following year.
Q: Where does borage grow best?
A: Borage prefers a sunny, sheltered position in well-drained, moisture-retentive soil.
Q: Is borage an annual or a perennial?
A: Borage is an annual herb.
Q: Is borage an invasive plant?
A: Borage is often referred to as invasive because of its rampant self-seeding habit. The seedlings are easily identified and removed, so it rarely becomes a major problem.
