The fragrant perennial from the genus Lavandula is beloved by gardeners for its aromatic foliage and vibrant purple blooms. Achieving a thriving, long-lived lavender plant depends on the precise timing of its purchase and planting. Successful establishment hinges on allowing the root system to develop fully before facing the stress of summer heat or winter cold. This careful timing ensures the plant focuses its energy on building a robust foundation. Understanding the best seasonal windows for introducing lavender to the garden makes a significant difference in its overall health and longevity.
Optimal Timing for Established Plants
The most widely recommended time to purchase and transplant pre-grown lavender plants is in the mid-spring to early summer. This window begins once the danger of the last hard frost has passed and the soil temperature has warmed, ideally reaching around 60°F. Planting during this period allows the young plant to capitalize on the entire growing season to establish its roots before its first winter dormancy.
When acquiring a plant from a nursery, gardeners should inspect the root system to ensure it is not root-bound, which can inhibit future growth. A healthy root ball shows white, firm roots that have not begun circling the inside of the pot.
Once the plant is home, “hardening off” is necessary to acclimatize it to the outdoor environment. This involves gradually increasing the plant’s exposure to direct sunlight, wind, and temperature fluctuations over one to two weeks. Initially, the plant should be placed in a sheltered, shaded area for just a few hours a day. Slowly increasing the duration and intensity of its outdoor exposure toughens the plant’s cell structure, reducing the shock it will experience when permanently planted.
The Alternative: Purchasing for Fall Planting
A successful secondary window for planting established lavender is in the late summer or early fall, often preferred by gardeners in milder climates. This strategy aims to introduce the plant roughly six to eight weeks before the first expected deep freeze. The warm soil temperatures remaining from summer encourage rapid root growth, while cooler air temperatures reduce the plant’s stress and water needs.
The benefit of fall planting is that it allows the plant to set a strong root system without the demands of simultaneous top growth or flowering. This deep root establishment provides an advantage for the plant’s survival through the winter and prepares it for vigorous growth when spring arrives.
Purchasing and planting too late in the fall prevents the roots from establishing sufficiently before the ground freezes. Insufficiently rooted plants are susceptible to “winter kill,” especially if the soil is cold and poorly drained, which can lead to fatal root rot. Gardeners in regions with harsh, early winters should defer planting until the following spring to avoid this risk.
When to Buy and Start Lavender Seeds
For those who prefer to grow lavender from seed, they must be purchased and started indoors well in advance of the outdoor planting season. Lavender seeds require a lengthy head start, typically needing to be sown indoors 10 to 12 weeks before the last anticipated spring frost date. This early timing accounts for the species’ slow and often erratic germination rate.
The seeds of many lavender varieties benefit from a cold stratification period. This involves subjecting them to cold, moist conditions to mimic natural winter exposure, which encourages uniform germination once the seeds are moved indoors. Using a heat mat to maintain a consistent soil temperature around 70°F also promotes successful sprouting.
Since growing lavender from seed is more challenging and time-intensive than using established transplants, seeds must be purchased in the late winter or very early spring. This ensures all necessary pre-treatment and indoor growing time is accounted for before the seedlings are ready to be hardened off and planted outdoors after the last frost.