Borage in Zone 7B — Desert Southwest

Borage is a fantastic addition to any Desert Southwest garden. Its vibrant blue, star-shaped flowers are not only beautiful but also attract pollinators to your garden. Plus, the young leaves and flowers have a refreshing cucumber-like flavor, perfect for salads and drinks, which is especially welcome during our hot summers.

Growing anything in the Desert Southwest comes with challenges like extreme heat and alkaline soil. But borage is surprisingly resilient, and with the right timing, you can enjoy a long harvest season. Our long growing season, about 245 days, means you can plant borage in spring and again in late summer for a continuous supply.

You can transplant borage seedlings outdoors in early to late March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the intense Desert Southwest sun and temperature swings.

Space the seedlings 12-18 inches apart to give them enough room to grow. Keep an eye on the weather forecast as you transplant; a late cold snap can damage young plants, so be prepared to cover them if necessary.

Direct sowing is the preferred method for borage in our region, as it establishes a strong root system. Sow borage seeds from mid-March through early September. The soil should be at least 60°F for optimal germination.

Prepare the soil by loosening it and mixing in some compost. Plant seeds about ½ inch deep and 12-18 inches apart. Borage is easy to direct sow and self-seeds readily, so be prepared to have it pop up in unexpected places!

Borage needs moderate watering, especially during our scorching summers. While it's an easy-going plant, it's definitely not drought-tolerant and will suffer in our arid climate without sufficient moisture.

During the spring and fall, water deeply about once a week, providing about 1 inch of water. In the peak of summer, increase watering to 2-3 times per week, ensuring the soil stays consistently moist. Use the finger test – if the top 2 inches of soil feel dry, it's time to water.

Water at the base of the plant to avoid wetting the leaves, which can encourage powdery mildew in our warm nights. Signs of underwatering include wilting leaves and slow growth, while overwatering can lead to yellowing leaves and root rot. A layer of mulch around the base of the plant helps retain moisture and regulate soil temperature.

You can expect your first harvest of borage flowers and leaves from early May through late November. Borage matures quickly, so you'll be enjoying those cucumber-flavored leaves about 55 days after planting.

Harvest the star-shaped blue flowers when they are fully open. For the leaves, pick young ones for the best flavor. Cut the stems just above a leaf node to encourage continued production.

As our first frost approaches in mid- November, harvest any remaining flowers and leaves. You can let the plant self-seed for next year's crop, but be mindful that it can spread aggressively.

Here are the top three problems you might encounter with borage in the Desert Southwest:

Self-Seeding Aggressively

• What it looks like: Borage seedlings popping up everywhere in your garden, even in places you didn't plant them.
• What causes it: Borage readily self-seeds, and our mild winters allow many of these seeds to germinate and grow.
• How to fix/prevent it: Deadhead flowers before they go to seed. Remove unwanted seedlings as soon as you see them. Consider growing borage in containers to limit its spread.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves promptly. 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: Long, spindly stems with fewer leaves, especially towards the base of the plant.
• What causes it: Insufficient sunlight, especially during the summer months when plants seek shade, can cause borage to stretch and become leggy.
• How to fix/prevent it: Plant borage in a location that receives full sun to part shade. Prune back leggy stems to encourage bushier growth. Provide support if needed.

Desert Southwest Specific Challenges The extreme heat and arid humidity of the Desert Southwest can stress borage, making it more susceptible to powdery mildew. Monsoon moisture can exacerbate fungal issues. Providing adequate shade during the hottest part of the day and ensuring good air circulation are crucial for borage summer survival here.

Borage makes a great companion plant for several vegetables and herbs in the Desert Southwest garden. Plant it near tomatoes, squash, and cucumbers, as it attracts pollinators that will improve fruit set. Borage also supposedly deters tomato hornworms.

Strawberries also benefit from having borage nearby, as it is thought to improve their flavor. There are no widely known bad companions for borage, so you can plant it freely throughout your garden.