Borage in Zone 10A — Desert Southwest

Borage is a fantastic addition to any Desert Southwest garden. Its beautiful blue, star-shaped flowers are not only edible and delicious with a mild cucumber flavor, but they also attract pollinators to your garden. Plus, the young leaves add a unique taste to salads, making it a versatile herb to grow in our region.

While the extreme heat and alkaline soil of the Desert Southwest can be challenging, Borage is surprisingly adaptable, especially when you time your planting right. With our long 339-day growing season, you can enjoy borage for a good portion of the year with careful planning.

If you choose to transplant Borage, aim for early January through early February. This gives the plant a chance to establish itself before the worst of our summer heat hits. Be sure to harden off your seedlings for about a week before transplanting, gradually exposing them to the sun and wind.

Space your plants 12-18 inches apart to allow for good air circulation. Keep an eye on the weather forecast; even in January and February, we can get unexpected temperature swings, so be ready to protect young transplants with shade cloth if needed.

Direct sowing is the preferred method for Borage, and it's incredibly easy. You can sow seeds from mid January through mid October, taking advantage of our two growing seasons. Borage is known to self-seed readily, so be prepared for volunteers!

Prepare your soil by loosening it and adding some compost. Borage isn't too picky, but good drainage is always a plus in our alkaline soil. Sow seeds about 1/4 inch deep and keep the soil consistently moist until they germinate. Thin seedlings to 12-18 inches apart.

Borage needs moderate watering, which can be a bit tricky in our Desert Southwest climate. During the hottest part of the summer, Borage will need more frequent watering, maybe every other day, depending on your soil. In the cooler months, you can usually get away with watering once or twice a week.

Always check the soil moisture before watering. Stick your finger about 2 inches deep; if it feels dry, it's time to water. Aim for about 1 inch of water per week, adjusting based on rainfall and temperatures. Water at the base of the plant to avoid wetting the leaves, which can help prevent powdery mildew in our arid environment.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to root rot, indicated by yellowing leaves and a generally unhealthy appearance. A layer of mulch around the base of the plant will help retain moisture and regulate soil temperature.

You can expect your first harvest of Borage around mid March through early January, about 55 days after planting. The star-shaped blue flowers are ready to harvest when they are fully open. The young leaves are best harvested when they are small and tender.

To harvest, simply snip off the flowers or leaves with scissors or your fingers. Be gentle to avoid damaging the plant and encourage continued production. Regular harvesting will also prevent the plant from getting too leggy.

As late December approaches and the first frost threatens, you can either let your Borage plant die back naturally or try to protect it with a frost cloth. Remember that Borage self-seeds readily, so you'll likely have new plants popping up in the spring.

Borage is generally easy to grow, but here are a few problems you might encounter in the Desert Southwest:

Self-seeding aggressively

• What it looks like: Borage seedlings popping up everywhere you don't want them.
• What causes it: Borage is a prolific self-seeder, especially in our long growing season.
• How to fix/prevent it: Deadhead flowers before they go to seed, or pull up unwanted seedlings as they appear. You can also contain it by growing it in a large pot.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems. Leaves curl, yellow, and die.
• What causes it: Various fungi 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. 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, bare stems with leaves concentrated at the top.
• What causes it: Insufficient sunlight or too much fertilizer.
• How to fix/prevent it: Ensure your Borage plant gets at least 6 hours of sunlight per day. Avoid over-fertilizing. Prune back leggy stems to encourage bushier growth.

Desert Southwest Specific Challenges: The extreme heat of our summers can stress Borage, making it more susceptible to powdery mildew. Monsoon moisture can also create favorable conditions for fungal diseases. Providing adequate shade during the hottest part of the day and ensuring good air circulation can help mitigate these issues.

Borage is a great companion plant for many vegetables and herbs in the Desert Southwest.

• Tomatoes: Borage is said to deter tomato hornworms, a common pest in our region.
• Squash: It attracts pollinators, which are essential for squash production.
• Strawberries: Borage is believed to improve the flavor and growth of strawberries.
• Cucumbers: It can deter cucumber beetles.

Avoid planting Borage near fennel, as they can inhibit each other's growth. Keep in mind that Borage can spread easily, so give it enough space and monitor its growth to prevent it from crowding out other plants.