The transition from the active growing season to the chill of autumn signals a necessary change in care for lavender, a fragrant woody perennial. Proper attention during this time is required to ensure the plant’s longevity and robust health for the following spring. Preparing the plant for its period of dormancy prevents damage from winter weather and maintains the plant’s desirable compact shape. Focusing on structural cuts and environmental protection now will save the plant from becoming leggy or suffering cold damage.
Essential Fall Pruning
Pruning in the fall is a structural necessity for lavender, helping to create an airy, compact mound that is resistant to heavy snow or ice damage. This pruning should occur after the final flush of flowers has faded, typically in late summer or early fall. Pruning must be done no later than six weeks before the expected first hard frost. This timing allows the cuts to heal without stimulating tender new growth that freezing temperatures would kill.
The goal of this heavier cut is to remove spent flower spikes and about one-third of the current year’s green growth. Use sharp, clean shears to cut the stems back, aiming to leave two or three sets of leaves on the remaining portion. Maintaining this dome-like shape prevents the plant from splaying open and exposing the central woody base over time.
Avoid cutting into the old, brown, woody tissue at the base of the plant. Unlike many shrubs, lavender does not readily regrow from this “dead wood.” Severe cuts here can create permanent, bare patches or even kill the entire plant. Always ensure you are cutting just above a visible set of green leaves or new shoots, which guarantees the presence of meristematic tissue ready to generate next year’s growth.
Winterizing and Cold Protection
The primary threat to lavender in winter is excessive moisture that leads to root rot. Lavender requires excellent drainage, especially when semi-dormant, as it is a Mediterranean plant. To mitigate the risk of “wet feet,” stop watering entirely in late fall and ensure the soil around the plant remains dry.
In colder climates, applying a protective layer of coarse material helps insulate the crown while allowing air circulation. Use materials like pea gravel, bark chips, or pine needles. These materials will not compress and hold excessive moisture against the woody stems like fine organic mulches. This thin layer helps to regulate soil temperature, reducing damaging freeze-thaw cycles that can heave shallow-rooted plants out of the ground.
Potted lavender plants are particularly vulnerable because their root systems are exposed to cold air on all sides. Before temperatures drop consistently below freezing, move containers to an unheated, sheltered location, such as a cold frame, garage, or shed. Placing the pot on bricks or pot feet elevates it slightly to maintain proper drainage and prevent the roots from sitting in standing water or freezing to the ground.
Harvesting and Propagation
The late-season growth provides a final opportunity to utilize the aromatic properties of the plant and expand your stock before winter dormancy. Any remaining flower spikes that appear in the early fall should be harvested just as the buds begin to open, securing the highest concentration of volatile oils. Tie these stems into small bundles and hang them upside down in a dark, dry area with good air circulation for a week or two until fully dried.
The pruned material from the fall cutback contains ideal candidates for propagation through semi-ripe cuttings. Select healthy, current-season stems that are firm at the base but still flexible at the tip. These cuttings, taken in early fall, have the best chance of rooting before winter begins.
Prepare cuttings by stripping the lower leaves and dipping the cut end into a rooting hormone. Place these prepared stems into a well-draining, sterile rooting medium, such as a mix of perlite and peat. Protecting these new starts in a cold frame or a bright, cool indoor location over winter allows them to establish a strong root system, ready for planting the following spring.