Borage in Zone 7A — Northern California

Borage is a fantastic addition to any Northern California garden. Its vibrant blue, star-shaped flowers are not only beautiful, but also attract pollinators to your garden. The leaves have a refreshing cucumber-like flavor, perfect for adding to salads or cool drinks during our dry summers. Plus, it's incredibly rewarding to grow, offering continuous harvests throughout our long growing season.

Even with our Mediterranean climate, gardening here has its challenges, like drought and increasingly warm summers. However, Borage is surprisingly resilient, and with our extended 235-day growing season, you'll have plenty of time to enjoy its benefits. With a little planning, you can make Borage thrive in your NorCal garden.

You can transplant Borage seedlings outdoors from early March through early April. Before planting, be sure to harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of sunlight and increase the time each day.

When transplanting, space your Borage plants about 12-18 inches apart. Keep an eye on the weather forecast; we sometimes get late-season cold snaps that can stress young plants, so be prepared to cover them if necessary.

Direct sowing is the preferred method for Borage, and it's very easy to do. You can sow seeds directly into the garden from mid March through early September. Borage loves warmer soil, so waiting until the soil has warmed up a bit (around 60°F) will improve germination rates.

Prepare your garden bed by loosening the soil and removing any weeds. Sow seeds about ½ inch deep and 12-18 inches apart. Keep the soil consistently moist until the seedlings emerge, which usually takes about a week or two. Borage self-seeds readily, so be prepared for new plants to pop up in unexpected places!

Borage needs moderate watering, especially during our hot, dry summers here in Northern California. While it's relatively easy-going, it's not truly drought-tolerant and will perform best with consistent moisture.

During the spring and fall, when temperatures are milder, check the soil moisture regularly. Stick your finger about 2 inches deep into the soil; if it feels dry, it's time to water. In the heat of summer, you might need to water every few days, providing about 1 inch of water per week. Water at the base of the plant to avoid wetting the foliage, which can help prevent fungal diseases in our low-humidity environment.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to root rot, indicated by yellowing leaves and a generally unhealthy appearance. Mulching around your Borage plants with a layer of organic material like compost or wood chips can help retain moisture in the soil, reduce evaporation, and keep the roots cool during our hot summers.

You can expect your first Borage harvest starting in mid May and continuing through mid November in our climate. Borage is ready to harvest about 55 days after planting. The star-shaped blue flowers are ready to pick when they are fully open. The young leaves are also edible and can be harvested at any time.

To harvest the flowers, simply snip them off with scissors or your fingers. For the leaves, harvest the younger, more tender leaves for the best flavor. Harvest regularly to encourage continued production of both leaves and flowers. As our first frost approaches in early November, you can harvest any remaining flowers and leaves.

Here are some common problems you might encounter growing Borage in Northern California:

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 is a prolific self-seeder, especially in our long growing season. The seeds drop and readily germinate.
• How to fix/prevent it: Deadhead the flowers before they go to seed to prevent unwanted seedlings. You can also collect the seeds for future planting or to share with friends. Thin out unwanted seedlings as they appear.

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. While we have low humidity, morning fog can create favorable conditions.
• 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, stretched stems with sparse leaves, especially if not getting enough sunlight.
• What causes it: Insufficient sunlight or overcrowding.
• How to fix/prevent it: Ensure your Borage plants are getting at least 6 hours of sunlight per day. Thin out plants to provide adequate spacing. Prune back leggy stems to encourage bushier growth.

Northern California Specific Challenges: Our moderate-to-hot summer heat can stress Borage if it's not adequately watered, and while powdery mildew isn't as rampant here as in more humid climates, it can still be an issue. Consistent watering and good air circulation are key to keeping your Borage healthy.

Borage is a great companion plant for several vegetables and herbs in the Northern California garden.

Good companions include:

• Tomatoes: Borage attracts beneficial insects, like bees and hoverflies, that help pollinate tomato flowers, leading to better fruit set.
• Squash and Cucumbers: Borage deters squash bugs and cucumber beetles, protecting these vulnerable plants.
• Strawberries: Borage is believed to improve the flavor and growth of strawberries.

Avoid planting Borage near fennel, as they can inhibit each other's growth.