Borage in Zone 4A — Mountain West

Borage is a fantastic addition to any Mountain West garden. The star-shaped blue flowers are not only beautiful, but they attract pollinators like crazy, which is essential for a successful garden at our high altitude. Plus, the leaves have a unique cucumber-like flavor that adds a refreshing twist to salads and drinks, and the flowers are edible too!

Our short growing season (around 118 days) and intense sun can be a challenge, but borage is surprisingly resilient. By timing your planting right, you can enjoy a continuous harvest of both leaves and flowers throughout our brief but beautiful summer.

If you're starting borage indoors, aim to transplant seedlings outdoors from early May through early June, after the risk of hard frost has passed. Remember that late temperature swings are known to happen here in the Mountains, so keep an eye on the forecast.

Before transplanting, harden off your seedlings by gradually exposing them to the outdoors for about a week. Start with an hour or two of shade, increasing the time and sun exposure each day.

Space your borage plants 12-18 inches apart to allow for good air circulation. This helps prevent problems later in the season.

Direct sowing is the preferred method for borage, and it's incredibly easy. You can sow seeds directly into your garden from mid May through early July. Just make sure the soil has warmed up a bit – borage prefers a soil temperature of at least 60°F (15°C) to germinate well.

Prepare your garden bed by loosening the soil and adding some compost. Even though borage tolerates our alkaline soil, a little organic matter helps. 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 to have new plants popping up in unexpected places next year!

Borage needs moderate watering, especially during our dry Mountain West summers. While it's fairly easy-going, don't let it completely dry out.

During the peak of summer, when temperatures are around 85°F, water deeply about once a week. Use the finger test: stick your finger about 2 inches into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week.

Water at the base of the plant to avoid wetting the leaves, which can encourage powdery mildew in our cool nights. Mulching around your borage plants with straw or wood chips helps retain moisture in our dry climate and keeps the soil cooler. Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to root rot, so make sure the soil drains well.

You can expect your first harvest of borage flowers and leaves from mid July through late September, about 55 days after sowing. The star-shaped blue flowers are ready to harvest when they are fully open.

Harvest leaves when they are young and tender for the best flavor. Simply snip off the leaves or flowers with scissors, being careful not to damage the plant.

To encourage continuous production, harvest regularly. Deadheading spent flowers will also help prevent the plant from going to seed too quickly. As our first frost approaches in mid- September, harvest any remaining leaves and flowers. You can dry the flowers for later use or add the leaves to compost.

Here are some common issues you might encounter with borage in the Mountain West:

Self-seeding aggressively

• What it looks like: Numerous borage seedlings popping up throughout your garden and surrounding areas.
• What causes it: Borage readily self-seeds, and the seeds can remain viable in the soil for several years.
• How to fix/prevent it: Deadhead spent flowers before they go to seed. Remove unwanted seedlings promptly. Consider growing borage in containers 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. 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: Tall, spindly plants with fewer leaves and flowers.
• What causes it: Insufficient sunlight or overcrowding.
• How to fix/prevent it: Ensure your borage plants receive at least 6 hours of sunlight per day. Thin out plants to provide adequate spacing. Prune back leggy stems to encourage bushier growth.

Mountain West Specific Challenges: The intense UV radiation at our altitude can sometimes stress borage plants, making them more susceptible to powdery mildew. The dry air and lack of humidity can also make it challenging to maintain consistent soil moisture. Monitor your plants closely and adjust your watering schedule as needed.

Borage is a great companion plant for many garden vegetables and herbs. It attracts pollinators, which benefits tomatoes, squash, strawberries, and cucumbers. It is believed to deter tomato hornworms and cabbage moths.

Avoid planting borage near fennel. Fennel inhibits the growth of many plants, including borage.