Lavender in Zone 5B — Great Plains

Lavender is worth growing in the Great Plains for its fragrance, beauty, and versatility. Imagine the scent wafting through your garden on a warm summer evening, the bees buzzing happily around the purple blooms. Plus, it's relatively low-maintenance once established, a big win with our variable rainfall and often intense summer heat.

Our region has its share of gardening challenges – wind, extreme temperature swings, and the occasional hail – but with careful planning and timing, you can successfully grow lavender. Our 178-day growing season gives us a solid window, especially if you start your plants indoors or buy established starts.

Starting lavender from seed indoors is possible, but it can be slow and a bit tricky. It's worth considering if you want a large number of plants or specific varieties not readily available as starts. Otherwise, buying transplants is the way to go.

If you're up for the challenge, start your seeds indoors from mid-February through early March, about 10 weeks before you plan to transplant. Use seed trays with a good seed-starting mix, provide warmth (a heat mat helps), and ensure plenty of light, especially with our variable spring weather. Bottom watering is key to prevent damping off.

Transplant your lavender seedlings outdoors from early to late May, once the risk of frost has passed. 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 we often experience.

Space the plants 12-18 inches apart to allow for good air circulation, which is crucial for preventing fungal diseases. Keep an eye on the forecast for late frosts; even though lavender is hardy, young transplants can be vulnerable. Remember, buying starts is often more reliable in our region due to the relatively short growing season and lavender's slow growth from seed.

Watering lavender correctly is critical, especially in the Great Plains, where we can swing from drought to periods of heavy rain. Lavender is very drought-tolerant and thrives in poor, dry soil. Overwatering is a much bigger threat than underwatering.

During the first growing season, water deeply but infrequently. Let the soil dry out almost completely between waterings. Use the "finger test": stick your finger into the soil about 2 inches deep. If it's dry, it's time to water. Usually, about 1 inch of water per week is sufficient, depending on rainfall. Water at the base of the plant to avoid wetting the foliage, especially with our low-to-moderate humidity.

Established lavender plants need very little supplemental watering, even during our hot summers. Yellowing leaves can indicate overwatering, while wilting can signal underwatering. A light layer of gravel mulch around the base of the plant can help improve drainage and prevent moisture from sitting around the crown.

Pruning is essential for maintaining the shape and vigor of your lavender plants. Deadhead spent flowers throughout the growing season to encourage continued blooming.

After the main flowering period, from early August through mid September, prune the plant to shape it into a neat mound, cutting back by about one-third. Be careful not to cut into the old wood, as lavender doesn't typically regrow from there. In late fall, as the first frost approaches around mid- October, you can do a light cleanup, removing any dead or damaged stems.

You can expect your first lavender harvest from early August through mid 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, for the best quality. To encourage continued production, cut above a set of leaves. You can dry the harvested lavender upside down in bundles in a dark, well-ventilated place. As the first frost approaches around mid- October, harvest any remaining flower stems to dry or use fresh.

Lavender, while generally low-maintenance, can face a few challenges in the Great Plains. The top three problems are:

Root Rot from Overwatering

• What it looks like: Yellowing leaves, wilting, and eventually, the plant collapses.
• What causes it: Soggy soil due to overwatering or poor drainage. Our variable rainfall can exacerbate this, especially if we have periods of heavy rain followed by high humidity.
• How to fix/prevent it: Ensure excellent drainage by planting in well-draining soil and avoiding overwatering. Amend heavy clay soils with gravel or sand.

Shab Disease

• What it looks like: Brown or black spots on the stems and leaves, often starting at the base of the plant.
• What causes it: A fungal disease that thrives in humid conditions. While our humidity is generally low-to-moderate, periods of high humidity can create favorable conditions for the disease.
• How to fix/prevent it: Improve air circulation by spacing plants adequately and pruning regularly. Remove and destroy any infected plant material.

Phytophthora Root Rot

• What it looks like: Similar to root rot from overwatering, but often more rapid and severe. The roots will be dark and mushy.
• What causes it: A soilborne pathogen that attacks the roots, especially in wet conditions.
• How to fix/prevent it: Prevention is key. Ensure excellent drainage, avoid overwatering, and consider using raised beds to improve soil drainage.

Great Plains Specific Challenges: Our hot summers and variable rainfall mean that drainage is crucial for lavender. While the plants are drought-tolerant, prolonged periods of dryness can stress them, making them more susceptible to disease. Monitor your plants carefully and adjust your watering schedule as needed.

Good companion plants for lavender in the Great Plains include rosemary, thyme, sage, and roses. Rosemary, thyme, and sage share similar growing requirements—full sun and well-drained soil—making them ideal companions. Roses benefit from lavender's pest-repelling properties.

Avoid planting mint near lavender. Mint spreads aggressively and can quickly take over, competing with lavender for resources. Plus, mint prefers moist soil, which is the opposite of what lavender needs.