Lavender in Zone 6B — Midwest

Lavender is absolutely worth growing in your Midwest garden. The scent alone is intoxicating, and the flowers are fantastic in teas, baked goods, and crafts. Plus, seeing those purple blooms thrive in your garden gives you a real sense of accomplishment.

We know Midwest weather can be unpredictable, with those cold winters and occasional summer heat spells. But with a little planning and attention to timing, you can absolutely grow beautiful lavender here. Our 183-day growing season gives you plenty of time to enjoy these fragrant blooms.

Starting lavender from seed indoors is possible, but be warned, it can be slow and a bit fussy. Honestly, many Midwest gardeners find it easier to buy established starter plants. But if you're up for the challenge, go for it!

If you're starting indoors, aim for mid February through early March. That gives you about 10 weeks to get them going before transplanting. Use seed trays with a good seed-starting mix, provide warmth (a heat mat helps), and make sure they get plenty of light – a grow light is almost essential. Bottom watering is a great way to keep the soil consistently moist without overdoing it. Keep in mind that our springs here in the Midwest can be moderate-to-late, so be patient.

Transplanting lavender outdoors should happen late April through mid May, once the danger of frost has passed. But always watch the forecast for a late frost! Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space your lavender plants about 12-18 inches apart to give them room to grow into their mature size. While seedlings can be touchy, buying starts is often the easiest route for reliable results in our region.

Watering lavender correctly is crucial, especially in the Midwest where we have moderate-to-humid summers and fairly wet summers. Remember, lavender is drought-tolerant and thrives in drier conditions. Overwatering is a much bigger threat than underwatering.

During the first growing season, water your newly transplanted lavender every week or so, giving them about an inch of water. After that, let rainfall be your guide. Use the "finger test" – stick your finger about 2 inches deep into the soil. If it's dry, it's time to water. In general, you'll only need to water established lavender during extended dry spells. Always water at the base of the plant to avoid getting the foliage wet, which can promote fungal diseases in our humid climate.

Yellowing leaves can be a sign of overwatering, while wilting leaves indicate underwatering. A light mulch of gravel or small stones can help improve drainage and keep the soil from staying too wet.

Pruning is essential for keeping your lavender plants healthy and productive. The key is to deadhead spent flowers and shape the plant after flowering.

After the first flush of blooms in late summer, prune back the flower stems, cutting back by about 1/3. This encourages bushier growth and more blooms. Be careful not to cut into the old, woody growth, as it won't regrow. As the first frost approaches around mid- October, leave any remaining foliage in place to protect the plant during the winter.

You can expect your first lavender harvest in late July through early September, about 90 days after planting. The best time to harvest is when the flower buds are showing color but haven't fully opened yet.

Cut the flower stems long in the morning, after the dew has dried. This is when the fragrance is most intense. To dry your lavender, tie the stems into small bundles and hang them upside down in a cool, dark, and dry place. Regular harvesting encourages continuous production throughout the summer. As the first frost approaches around mid- October, harvest any remaining blooms to enjoy indoors.

Lavender can face a few problems in the Midwest, mainly related to our climate and soil. Here are three common issues and how to address them:

Root Rot from Overwatering

• What it looks like: Yellowing leaves, wilting, stunted growth, and eventually, the plant dies.
• What causes it: Overwatering, poor drainage, and heavy clay soil, all common in the Midwest. Our wet-summer rainfall can exacerbate this problem.
• How to fix/prevent it: Plant lavender in well-draining soil, amend heavy clay soil with compost and gravel, and water sparingly. Make sure the planting location has excellent drainage.

Shab Disease

• What it looks like: Brown or black spots on the leaves and stems, often accompanied by a general decline in the plant's health.
• What causes it: A fungal disease that thrives in humid conditions. The moderate-to-humid climate of the Midwest makes lavender susceptible, especially with overhead watering.
• How to fix/prevent it: Improve air circulation around the plants by spacing them properly and pruning regularly. Remove and destroy any infected plant material. Avoid overhead watering.

Phytophthora

• What it looks like: Similar to root rot, with yellowing leaves, wilting, and eventual plant death. The roots will appear dark and mushy.
• What causes it: A soilborne pathogen that thrives in wet conditions. Heavy clay soil and overwatering contribute to the problem.
• How to fix/prevent it: Ensure excellent drainage and avoid overwatering. If you suspect phytophthora, remove and dispose of the infected plant and surrounding soil. Consider planting lavender in raised beds or containers to improve drainage.

Midwest Specific Challenges: The combination of moderate-to-hot heat, moderate-to-humid humidity, and wet-summer rainfall in the Midwest creates a challenging environment for lavender. Proper soil preparation, careful watering, and good air circulation are essential for success.

Lavender makes a great companion plant for several herbs and flowers in the Midwest garden. Rosemary, thyme, and sage are all excellent choices because they share similar growing requirements – full sun and well-drained soil. Plus, their aromatic oils can help deter pests that might bother your lavender. Roses also benefit from being planted near lavender, as the lavender can help repel aphids and other rose pests.

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