Borage in Zone 5A — Northeast

Borage is a fantastic addition to any Northeast garden. The beautiful blue, star-shaped flowers attract pollinators, and the cucumber-flavored leaves and flowers add a unique touch to salads and drinks. Plus, it's just plain satisfying to grow something a little different in our short growing season.

Our 153-day growing season definitely keeps us on our toes. Between the risk of late spring frosts and the inevitable early fall chill, you might worry that borage is too tender for our region. But borage is surprisingly hardy, and with a little planning, you can easily enjoy a bountiful harvest.

If you're starting borage indoors, aim to transplant it outdoors mid April through mid May. This gives the plants a head start, but avoids the worst of the spring frosts we often see in the Northeast.

Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the cooler temperatures and stronger sunlight. Space the plants 12-18 inches apart to allow for good air circulation.

Keep an eye on the weather forecast. A late frost can still sneak in, so be prepared to cover your young plants if needed. A simple row cover or even an old blanket can make all the difference.

Direct sowing is the easiest and most common way to grow borage in the Northeast. You can sow seeds directly into your garden from early May through late July. This wide window allows you to stagger plantings for a continuous harvest.

Borage prefers well-drained soil. Before sowing, loosen the soil and amend with compost to improve fertility. Soil temperature should be at least 60°F for optimal germination. Sow seeds about ½ inch deep and 12-18 inches apart.

Borage is easy to direct sow, and it self-seeds readily. Be prepared to find volunteer plants popping up in your garden the following year!

Borage needs moderate watering, especially during dry spells. While it's a relatively easy-going plant, consistent moisture is key for healthy growth and abundant flowering.

In the Northeast, with our even rainfall and moderate humidity, a good rule of thumb is to water deeply once a week, providing about 1 inch of water. Use the "finger test" to check soil moisture: stick your finger about 2 inches into the soil. If it feels dry, it's time to water.

Water at the base of the plant to avoid wetting the leaves, especially with our moderate-to-humid conditions. Overhead watering can increase the risk of fungal diseases.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to root rot, indicated by yellowing leaves and a mushy stem base. A layer of mulch, like straw or wood chips, helps retain moisture and suppress weeds – a great addition for our sometimes rocky New England soil.

Your first borage harvest in the Northeast should be late June through early October, about 55 days after sowing. Look for the star-shaped blue flowers to be fully open – they're ready to pick!

To harvest, gently snip the flowers or leaves with scissors or pruners. Avoid pulling, which can damage the plant. Young leaves are best for eating, as they have the mildest cucumber flavor. Harvest regularly to encourage continued production.

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

Here are a few common issues you might encounter growing borage in the Northeast:

Self-seeding aggressively

• What it looks like: Numerous borage seedlings popping up everywhere in your garden the following spring.
• What causes it: Borage is a prolific self-seeder. Seeds drop from the plant and germinate readily in the spring.
• How to fix/prevent it: Deadhead flowers before they go to seed. Pull up unwanted seedlings as they emerge. Consider growing borage in a container to limit its spread.

Powdery mildew

• What it looks like: White or grayish powdery coating on leaves, stems.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity – fairly typical conditions for a Northeast summer. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation through spacing. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is surprisingly effective.

Can become leggy

• What it looks like: Long, weak stems with sparse foliage.
• What causes it: Insufficient sunlight or overcrowding.
• How to fix/prevent it: Plant in full sun to part shade. Thin out plants to provide adequate spacing. Pinch back the tips of stems to encourage bushier growth.

Northeast Specific Challenges: Our moderate heat, moderate-to-humid humidity, and even rainfall can be a mixed blessing for borage. The humidity can increase the risk of powdery mildew, so good air circulation is essential. On the other hand, the consistent rainfall can help keep the plants adequately watered.

Borage is a great companion plant for several vegetables and herbs in your Northeast garden.

Good companions:

• Tomatoes: Borage attracts pollinators, which can improve tomato yields.
• Squash: Borage can deter squash bugs and other pests.
• Strawberries: Borage is said to improve the flavor of strawberries.
• Cucumbers: The cucumber flavor of borage complements cucumbers in salads.

Bad companions:

• Avoid planting borage near members of the Brassica family (cabbage, broccoli, kale). Borage can attract cabbage moths, which can damage these plants.