Lavender in Zone 8A — Pacific Northwest

Lavender is a fantastic addition to any Pacific Northwest garden. Its fragrance is wonderful, it’s versatile for culinary and craft uses, and the deep purple blooms are gorgeous. Plus, our cool nights really bring out the best flavor in herbs. The satisfaction of harvesting your own lavender for sachets, teas, or even baked goods is hard to beat.

We do have some unique gardening challenges here, but Lavender is well-suited to our climate if you time things right. Our 203-day growing season gives you plenty of time to get a harvest. Just be mindful of our wet springs when you're getting started.

Starting Lavender from seed indoors is possible, but it can be slow and a bit finicky. If you're up for a challenge, go for it! Otherwise, buying starts from a local nursery is a reliable way to get a jump start.

If you're starting indoors, sow seeds early to late February, about 10 weeks before you plan to transplant. Use seed trays with a well-draining seed starting mix. Lavender needs warmth to germinate, so a heat mat can be helpful. Place the trays under grow lights, as our overcast spring days don't provide enough light for seedlings. Water gently from the bottom to avoid damping off.

Transplant your Lavender seedlings outdoors late April through mid May. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Plant Lavender 12-18 inches apart in a sunny spot with well-draining soil. Be prepared for cool soil at this time of year. Amend your garden soil with compost or other organic matter to improve drainage. If we get a late spring frost, cover your new transplants to protect them. Honestly, buying starts avoids this hassle and gets you to blooms faster.

Lavender is very drought-tolerant and thrives in dry conditions, which makes it a great fit for our dry summer months. Overwatering is a far bigger threat in the Pacific Northwest than underwatering, especially with our wet springs. Excellent drainage is key.

During the wet spring, you likely won't need to water at all unless we have an unusually dry spell. Once the dry summer months arrive, water deeply but infrequently, about once every 1-2 weeks, depending on rainfall. Use the finger test: stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week, including rainfall. Water at the base of the plant to avoid getting the foliage wet, which can encourage fungal diseases in our sometimes humid conditions.

Signs of underwatering include wilting or drooping leaves. Overwatering can cause yellowing leaves and potentially root rot. A light layer of gravel mulch around the base of the plant can help improve drainage and prevent soil from splashing onto the foliage.

Pruning is important for maintaining the shape and health of your Lavender plant. Deadhead spent flowers throughout the blooming season to encourage more blooms. This also keeps the plant looking tidy.

After the main flowering period, late July through early September, prune the plant back by about one-third, shaping it into a nice mound. Be careful not to cut into the old wood, as Lavender doesn't typically regrow from there. As first frost approaches in late October, avoid any heavy pruning, as this can stimulate new growth that won't have time to harden off before winter.

You can expect your first Lavender harvest late July through early September. Look for flower stems where the buds are showing good color but haven't fully opened yet. This is when the fragrance and oil content are at their peak.

Harvest by cutting the long stems in the morning, after the dew has dried. Use sharp scissors or pruning shears to make a clean cut. Gather the stems into small bundles and tie them together with twine. Hang the bundles upside down in a cool, dark, and dry place to dry. This usually takes a few weeks.

Deadheading spent blooms encourages continued production throughout the season. As first frost approaches in late October, harvest any remaining flower stems to dry and use.

Here are some common problems you might encounter growing Lavender in the Pacific Northwest:

Root Rot from Overwatering

• What it looks like: Yellowing leaves, wilting, and a general decline in plant health. The roots may be brown and mushy.
• What causes it: Overwatering, especially in heavy clay soils with poor drainage. Our wet springs can exacerbate this issue.
• How to fix/prevent it: Ensure your Lavender is planted in well-draining soil. Amend heavy clay soils with compost or other organic matter. Water sparingly, especially during the wet spring months. Consider planting in raised beds or containers for better drainage.

Shab Disease

• What it looks like: Brown or black spots on stems and foliage, often accompanied by a general decline in plant vigor.
• What causes it: A fungal disease that thrives in humid conditions. While our summers are dry, we can still have periods of high humidity, especially near the coast.
• How to fix/prevent it: Provide good air circulation around your plants. Avoid overhead watering. Remove and destroy any infected plant material. Apply a fungicide if necessary, following label instructions carefully.

Phytophthora Root Rot

• What it looks like: Similar to root rot caused by overwatering, with yellowing leaves, wilting, and root decay.
• What causes it: A soilborne pathogen that thrives in wet conditions. It's more prevalent in poorly drained soils.
• How to fix/prevent it: Improve soil drainage by amending with compost or planting in raised beds. Avoid overwatering. Use disease-free planting material. There are also some soil treatments available that can help prevent Phytophthora.

Pacific Northwest Specific Challenges: While Lavender generally loves our dry summers, our wet springs and occasional periods of high humidity can create challenges. The key is to focus on providing excellent drainage and avoiding overwatering. Mulching with gravel can also help improve drainage and prevent soil from splashing onto the foliage, reducing the risk of fungal diseases.

Lavender makes a great companion plant for several other herbs and flowers in the Pacific Northwest. Rosemary, thyme, and sage are all excellent choices because they share similar growing requirements: full sun and well-drained soil. They also attract beneficial insects that can help pollinate your Lavender. Roses also benefit from being planted near Lavender, as Lavender can help deter aphids and other pests that commonly attack roses.

Avoid planting Lavender near mint. Mint is a vigorous grower that can quickly spread and crowd out Lavender. Mint also prefers moist soil, which is the opposite of what Lavender needs to thrive.