Lavender in Zone 8A — Desert Southwest

Lavender thrives in our Desert Southwest gardens, bringing beauty, fragrance, and culinary possibilities right to your doorstep. Imagine strolling through your garden, the air filled with the calming scent of lavender, the bees buzzing happily around the purple blooms. Plus, it's a tough plant that can handle our alkaline soil and blazing sun once established.

Growing lavender here does come with challenges, mainly our extreme heat and the occasional monsoon downpour. But with careful timing and attention to watering, you can enjoy a thriving lavender patch. Our long, 265-day growing season actually gives you a nice window of opportunity to get it established.

Starting lavender from seed indoors in the Desert Southwest is possible, but it can be a bit slow and tricky. Honestly, most of us find it easier to buy established starts from a local nursery. But if you're up for the challenge, go for it!

If you want to try seeds, start them indoors in early to late January, about 10 weeks before you plan to transplant. Use seed trays with good drainage and a light, well-draining seed-starting mix. Bottom watering is key to prevent damping off. Provide warmth and plenty of light, especially since our spring character in the Desert Southwest tends to be very-early and can trick you.

Transplant your lavender seedlings outdoors from mid March through early April. Before you plant, harden them off by gradually exposing them to outdoor conditions for about a week. This prevents shock from our intense Desert Southwest sun. Space them 12-18 inches apart to allow for good air circulation.

Honestly, buying established plants from a local nursery is often the easiest way to go. They're already adapted to our conditions, and you'll get blooms much faster. Just be ready for temperature swings around transplant time; protect young plants if a late cold snap threatens.

Lavender is very drought-tolerant and thrives in poor, dry soil, so avoid overwatering it. In the Desert Southwest, overwatering and humidity are the biggest threats to lavender's survival. Excellent drainage is essential.

During our active growing seasons (spring and fall), water deeply but infrequently. Let the soil dry out almost completely between waterings. Stick your finger about 2 inches deep into the soil; if it's dry, it's time to water. In the peak of our extreme summer heat, you might need to water once every 7-10 days, giving it about 1 inch of water each time. During the monsoon season, let the rains do the work.

Water at the base of the plant to avoid getting the foliage wet, since our arid climate can still trap moisture and cause problems. Signs of underwatering include wilting and yellowing leaves, while overwatering leads to root rot and a generally unhappy plant. A light layer of gravel mulch can help improve drainage and reduce evaporation.

Pruning is important for keeping your lavender plant healthy and productive. After the first flush of blooms in early to mid-summer, deadhead the spent flowers. This encourages the plant to produce more blooms later in the season.

You can also shape the plant into a nice, rounded mound at this time, cutting back by about 1/3. Be careful not to cut into the old wood, as lavender doesn't regrow from there. As the first frost approaches in late November, you can lightly tidy up the plant, but avoid heavy pruning at this time.

Your first lavender harvest in the Desert Southwest should be mid June through late July, about 90 days from transplanting. Look for flower stems where the buds are showing good color but aren't fully open yet. This is when the fragrance is most intense.

Harvest in the morning after the dew has dried. Cut the stems as long as possible, leaving several inches of green growth on the plant. Gather the stems into small bundles and hang them upside down in a cool, dark, well-ventilated place to dry. Deadheading spent blooms encourages continued production through the fall. Even as our first frost approaches in late November, you can still harvest any remaining blooms for drying.

Lavender, while generally tough, can face a few problems in the Desert Southwest:

Root Rot from Overwatering

• What it looks like: Yellowing leaves, wilting, and a general decline in plant health. The roots will be brown and mushy.
• What causes it: Overwatering, especially in poorly draining soil. Our monsoon season can exacerbate this.
• How to fix/prevent it: Ensure excellent drainage. Plant in raised beds or amend the soil with plenty of gravel. Water deeply but infrequently, and let the soil dry out between waterings.

Shab Disease

• What it looks like: Stunted growth, yellowing leaves, and eventual death of the plant.
• What causes it: A fungus that thrives in humid conditions.
• How to fix/prevent it: Improve air circulation around the plants by spacing them properly. Remove and destroy any infected plants.

Phytophthora

• What it looks like: Similar to root rot, with wilting, yellowing, and eventual death of the plant.
• What causes it: A soilborne pathogen that thrives in wet conditions.
• How to fix/prevent it: Ensure excellent drainage. Avoid overwatering. Use disease-free planting material.

Desert Southwest Specific Challenges: The extreme heat and intense sun can stress lavender plants, making them more susceptible to disease. Our alkaline soil can also be a challenge, so amend with compost to improve drainage and nutrient availability. Be especially vigilant during the monsoon season, as the combination of heat and humidity can create ideal conditions for fungal diseases.

Lavender benefits from companion planting in the Desert Southwest. Rosemary, thyme, and sage all share similar growing requirements: full sun, well-drained soil, and low water. They also attract beneficial insects that can help control pests. Roses also make good companions, as they appreciate similar conditions and the lavender can help deter aphids.

Avoid planting mint near lavender. Mint is very aggressive and can quickly take over, crowding out the lavender and stealing its water and nutrients. Plus, mint prefers moist soil, which is the opposite of what lavender needs to thrive in our arid climate.