Lavender in Zone 6B — Great Plains

Lavender is a fantastic addition to any Great Plains garden. Its fragrant blooms attract pollinators, and the scent is wonderfully relaxing. Plus, it's incredibly versatile – use it in cooking, crafts, or simply enjoy its beauty in your garden.

Growing lavender in our region comes with challenges like extreme temperature swings and variable rainfall. But with careful planning and attention to watering, you can successfully grow this beautiful herb. Our long growing season, stretching from early April to late October, gives lavender plenty of time to flourish.

Starting lavender from seed indoors is possible, but be warned: it can be slow and a bit tricky. If you're up for the challenge, start your seeds indoors from early to late February, about 10 weeks before you plan to transplant them outdoors.

Use seed trays with a well-draining seed starting mix and provide warmth (around 70°F) and plenty of light – a grow light is almost essential. Bottom watering is a great way to keep the soil consistently moist without overwatering the delicate seedlings. Keep in mind that our variable spring weather can make timing tricky, so be patient.

Transplant your lavender seedlings outdoors from late April through mid May, after the risk of hard frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the wind and temperature fluctuations common in the Plains.

Space your lavender plants 12-18 inches apart in a sunny spot with well-draining soil. Honestly, buying established starts from a local nursery is often the most reliable way to get a thriving lavender patch. They're already adapted to our conditions.

Lavender thrives on neglect, especially here on the Plains. Overwatering is a much bigger threat than underwatering. Once established, lavender is very drought-tolerant and prefers dry soil.

During the heat of summer, with typical highs around 93°F, water deeply but infrequently. Let the soil dry out almost completely between waterings. Stick your finger about 2 inches into the soil – if it's dry, it's time to water. Generally, an inch of water per week (including rainfall) is plenty. Water at the base of the plant to avoid wetting the foliage, which can lead to fungal problems in our low-to-moderate humidity.

Signs of underwatering include wilting or drooping leaves. Overwatering can cause yellowing leaves and, eventually, root rot. A light mulch of gravel or rock around the base of the plant can help improve drainage and reduce moisture retention, which is a good idea given our variable rainfall.

Pruning is essential for maintaining a healthy and productive lavender plant. Deadhead spent flowers throughout the growing season to encourage more blooms.

After the main flowering period, usually in late summer, prune your lavender plants to shape them into a neat mound. Cut back about one-third of the growth, but be careful not to cut into the old wood, as it won't regrow. As our first frost approaches around late October, stop pruning and allow the plant to harden off for winter.

You can expect your first lavender harvest from late July through early September, about 90 days after transplanting. Harvest the flower stems when the buds are colored but not fully open. This is when the fragrance is most intense.

Cut long stems in the morning, after the dew has dried. This helps to preserve the essential oils. To dry your lavender, tie the stems into small bundles and hang them upside down in a cool, dark, and well-ventilated place. Continue to harvest throughout the flowering season to encourage continued production.

As the first frost approaches in late October, harvest any remaining flower stems to dry and enjoy indoors.

Lavender, though relatively easy to grow, can face a few problems in the Great Plains. Here are three common ones:

Root rot from overwatering

• What it looks like: Yellowing leaves, wilting, and a general decline in plant health. Roots may be brown and mushy.
• What causes it: Soggy soil due to overwatering or poor drainage. This is exacerbated by our variable rainfall – a heavy downpour after a period of dryness can quickly lead to root rot.
• How to fix/prevent it: Ensure your lavender is planted in well-draining soil. Water deeply but infrequently, allowing the soil to dry out between waterings. Amend heavy clay soils with sand or gravel to improve drainage.

Shab disease

• What it looks like: Brown or black spots on the leaves and stems, often accompanied by a general weakening of the plant.
• What causes it: A fungal infection that thrives in humid conditions. Although our humidity is generally low-to-moderate, periods of wet weather can create favorable conditions for the disease.
• How to fix/prevent it: Improve air circulation around the plant by spacing plants adequately and pruning to remove crowded growth. Remove and destroy any infected plant material. Fungicides may be necessary in severe cases.

Phytophthora

• What it looks like: Sudden wilting and death of the plant, often affecting entire sections. The base of the stem may be dark and water-soaked.
• What causes it: A soilborne pathogen that attacks the roots, particularly in wet conditions.
• How to fix/prevent it: Ensure excellent drainage. Avoid overwatering. Use disease-free planting material. If you suspect Phytophthora, remove and destroy the affected plant and surrounding soil.

Great Plains Specific Challenges: The combination of hot summers, low-to-moderate humidity, and variable rainfall in the Great Plains can make growing lavender a bit of a balancing act. Watch your watering carefully, especially after periods of heavy rain, and choose a sunny location with excellent drainage.

Companion planting can help your lavender thrive in the Great Plains. Rosemary, thyme, and sage make excellent companions for lavender. These herbs share similar growing requirements – full sun and well-drained soil – and can help repel pests. Roses also make good companions, as they attract beneficial insects that can help keep your lavender healthy.

Avoid planting mint near lavender. Mint is a vigorous grower that can quickly outcompete lavender for resources. It also prefers moist soil, which is the opposite of what lavender needs.