Borage in Zone 5B — Midwest

Borage is a fantastic addition to any Midwest garden. Its edible, cucumber-flavored leaves and beautiful blue flowers make it both useful in the kitchen and attractive in the garden. Plus, it's incredibly satisfying to grow something that attracts pollinators and thrives in our fertile soil and warm summer conditions.

While Midwest weather can be unpredictable, with the occasional late frost and summer heat spells, borage is adaptable enough to handle it. Our 168-day growing season provides ample time to enjoy this plant, especially if you time your planting right.

You can transplant borage seedlings outdoors in mid-April through early May. Be sure to harden off your seedlings for about a week before transplanting. Gradually expose them to outdoor conditions to acclimate them.

Space the plants about 12-18 inches apart, giving them enough room to bush out. Keep an eye on the weather forecast—those unexpected cold snaps in late spring can still happen, so be ready to cover your young plants if needed.

Direct sowing is the easiest and most recommended method for growing borage here in the Midwest. You can start sowing seeds outdoors from late April through early August. Borage is super easy to direct sow and will even self-seed readily if you let it.

Prepare your soil by loosening it and making sure it's free of large clumps. Borage isn't too picky, but it appreciates well-draining soil. Sow the seeds about ½ inch deep and 12-18 inches apart. Keep the soil consistently moist until the seedlings emerge.

Borage needs moderate watering, which is pretty manageable in our Midwest climate, especially with our wet summers. During the hotter stretches, you'll want to pay closer attention to soil moisture.

Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Generally, an inch of water per week, whether from rainfall or irrigation, is sufficient. Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our moderately humid climate.

If the leaves start to droop and turn yellow, you're likely overwatering. If the leaves are wilting and the soil is bone dry, you're underwatering. A layer of mulch around the base of the plants helps retain moisture and keeps the soil cool during those summer heat spells.

You can expect your first harvest of borage around mid-June if you planted in late April, and you can continue harvesting through mid-October. Look for the vibrant blue, star-shaped flowers that are fully open—these are perfect for adding to salads or using as a garnish. The young leaves, which taste like cucumber, can be harvested anytime.

To harvest, simply snip off the flowers or leaves with scissors or your fingers. Avoid pulling or tugging, which can damage the plant. Regular harvesting encourages continued production, so don't be shy about using your borage.

As the first frost approaches in early October, harvest any remaining flowers and leaves. You can dry them for later use or let some of the plants go to seed if you want them to self-sow for next year.

Here are a few common problems you might encounter with borage in the Midwest:

Self-seeding aggressively

• What it looks like: Borage popping up everywhere you don't want it.
• What causes it: Borage readily self-seeds, and the seeds are quite viable.
• How to fix/prevent it: Deadhead flowers before they go to seed. If you want some self-seeding, allow a few plants to mature and drop seeds, but remove the rest.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves and stems.
• What causes it: Fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces favor it.
• How to fix/prevent it: Improve air circulation by spacing plants adequately and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective.

Can become leggy

• What it looks like: Tall, sparse plants with few leaves.
• What causes it: Insufficient sunlight or overly fertile soil.
• How to fix/prevent it: Ensure plants receive at least 6 hours of sunlight daily. Avoid over-fertilizing. Pruning can encourage bushier growth.

Midwest Specific Challenges: Our moderate-to-hot summers and moderate-to-humid conditions can sometimes encourage powdery mildew. Make sure to provide good air circulation and monitor your plants regularly. Our wet-summer rainfall means you might not need to water as often, but be sure to check the soil moisture.

Borage is a great companion plant for several vegetables and herbs in the Midwest garden. It's known to attract pollinators and beneficial insects, which can help improve yields and reduce pest problems.

Good companions include tomatoes (borage repels tomato hornworms), squash (it attracts pollinators that help with fruit set), strawberries (it deters pests), and cucumbers (it improves growth and flavor). Avoid planting borage near fennel, as they are not compatible and can inhibit each other's growth.