Borage flowers provide delightful splashes of blue for your garden. They attract loads of pollinators, have edible leaves and flowers, and are a medicinal herb. All around, borage, also sometimes called starflower, is a top choice for gardeners around the world. It is easy to germinate from seed, not too fussy once established, and often comes back each year without effort.
Borage can grow anywhere in the lower 48 states. Think about how amazing that is! If you’re anywhere between Maine and L.A., you can plant this garden mainstay. Starflower’s wide tolerance of climatic zones spans from zones 2-11 on the USDA plant hardiness map.
With some plants, it is best to start seeds indoors and transplant them outside once the plants are big enough. This is not the case with borage. Borage seeds do best when sown directly into the soil because they develop taproots. A taproot is a single, thick root that drives deep into the ground to find water. Smaller roots grow off this main root to provide the plant with nutrients and water.
Since taproots dive as deep into the soil as soon as possible, plants with taproots don’t thrive when started in small containers. If a taproot breaks during a transplant from the container to the ground, the plant will not recover. Plants with fibrous roots, on the other hand, are the sorts of plants that do well when started indoors. Enough botany 101, let’s get back to borage seeds.
So far we’ve determined you can sow the borage seeds directly into the ground anywhere in the lower 48. But how deep should you plant them and with what spacing?
Borage seeds are quite small. As a general rule of thumb, a smaller seed should be planted closer to the surface than a larger seed. For example, a sunflower seed, which is relatively big, should be planted about 1 inch (2.5 cm) underground. A starflower seed, on the other hand, should be just under the surface of the soil (less than 1cm). Sometimes, borage seeds will succeed when simply tossed onto the soil from above.
To plant the seeds, make a small divet in the soil with your pinky. Then, put a seed or two in there. Fill the divet back up with soil, but make sure to only fill it up to the previous level. Sometimes, people fill the divet with a material called vermiculite instead of soil. This is a mineral that absorbs tons of water. It is helpful for starting seeds because it keeps the seed moist during its critical germination period.
Borage plants can get to be fairly large, so sow the seeds about 12 inches (30cm) apart from each other. If the plants grow well and fill-out their entire space, you can thin them to every 24 inches. While it might be emotionally hard to pull out a precious plant, wildflowers tend to be healthier and more prolific when given more space. It’s worth experimenting for yourself! Try thinning one section and leaving a different section at 12-inch spacing. See which one you like better!
Seeds have a critical period during germination where they must stay moist. Since seeds have no access to water other than the soil directly around them, the soil must stay wet during the entire germination period for the seed to successfully establish. This is especially true once you see the cotyledons appear. Cotyledons are the first two leaves (sometimes one) of a plant. Once the plant has these cotyledons, it needs water to support them. At this point, the plant has a tiny, delicate root system that can’t search far for water. This means if the top inch of soil dries out, which happens quickly in a hot environment, the seedling will die. Thus, always keep your baby borages moist until you see the first set of true leaves (not cotyledons) develop. This is a good practice for starting any plant.
Borage seeds do best when planted just after the last frost. However, if you missed planting them in the spring, they will probably do just fine if you plant them in June or July.
While borages can come back every year as volunteers, they are an annual plant, not a perennial plant. Since they are often successful in reproducing, borage plants will develop seeds. Once ripe, these seeds will drop onto the soil underneath the plant.
In the spring, these seeds may germinate and make baby borage plants all on their own. If you want your borage to self-seed, keep the plant until fall. Once the plant begins to yellow, check to see if the seeds are almost black, not green, white, or yellow. If the seeds are black, they are ripe for next year’s crop.
If your borage plant has many ripe seeds you can collect them and give them to your friends and neighbors. You can also cut the plant and shake it over the ground to disperse the seeds. If you don’t want borage to self-seed (it can take over in some areas), cut it before it has a chance to ripen seeds.
One great reason to grow starflower is to eat it. The flower itself is edible. It’s bright blue color brings zesty accents to desserts and salads. When hosting a party, try putting a single borage flower in each slot of an ice cube tray. Fill the tray up with water and freeze. These floral ice cubes make any drink more exciting!
The young leaves are also edible. I tend to stay away from the older leaves because I don’t like the bristly hairs that cover them.
Various parts of the borage plant are used for plant-based remedies. People use the plant for aiding with diabetes, skin rashes, ADHD, heart disease, asthma, stroke, and even alcoholism. It is thought that the fatty acid found in the seeds may be one of the healing compounds in the plant.
If you want to grow borage for your own medicinal use, make sure to grow it safely. There are many aspects to consider when growing a plant for medicinal use.
My favorite reason to grow borage is for pollinators. The plants must produce abundant nectar and pollen because bees love borage. I plant borage near my other flowers to attract pollinators to my pollinator garden. A recent scientific study confirms borage’s usefulness in pollination.
The scientists conducted this study on the effects of borage plants on strawberry yields. The scientists compared the yield of strawberry plants with borage planted nearby to strawberry plants without nearby borage. They found that the strawberry plants near the borage yielded 35% more fruit and 33% more weight than the control strawberries!
Furthermore, they found that the strawberries grown near the borage plants were of higher market quality. Therefore, farmers could increase their strawberry yields and the price per pound of strawberries with borage plants nearby. This is most likely because the borage attracts better pollinators to the general area.
Perhaps you should plant borage near your tomatoes, squash, or other garden crops that need pollination!
I hope you enjoy all the delightful aspects of the borage plant. It is attractive, medicinal, pollinator-friendly, and edible. Who could ask for a better garden plant?