When and How Should I Prune Lavender?

Pruning is the single most important maintenance task for lavender, and getting it right determines whether the plant remains compact and productive for a decade or becomes a woody, sprawling disappointment within three years. The key principles are straightforward: prune twice a year, always cut into green wood rather than bare wood, and never take off more than one third of the overall plant height in a single session. Understanding the why behind these rules makes it far easier to apply them correctly in practice.

The spring prune — timing and technique

Prune lavender in early to mid spring, once you can see the new season's growth beginning to emerge as small green buds at the base of the previous year's shoots. In the UK this is typically late March to mid April. Cut each shoot back by about one third, to just above where you can see new green growth beginning. Use sharp, clean secateurs to make a single, angled cut. The goal is to create a rounded, compact mound with each stem shortened but still carrying several potential growth points from which new shoots will extend.

The post-flowering prune

Once the flower spikes have finished — typically in August for most angustifolia varieties — cut off all the spent flower stalks. Cut them back to just above the first leaves below the stalk. This is also a good moment to gently reshape the plant's outline and remove any shoots that are growing out at an awkward angle. This second trim keeps the plant tidy, prevents self-seeding, and on some varieties encourages a second light flush of flowers in September.

The golden rule: never cut into bare wood

Lavender does not regenerate reliably from old brown wood that has no leaves or green buds on it. Every cut you make must leave some visible green growth on the remaining stem below the cut. If you can see any green — even a single tiny bud — cutting to that point is safe. If the wood below is entirely bare and brown, do not cut there; those stems will simply die. This limits how drastically you can prune a neglected plant but is a firm boundary you should not cross.

Tools and hygiene

Use sharp, clean secateurs. Wipe the blades with methylated spirit or a diluted bleach solution between plants to avoid transferring fungal spores — particularly the Phomopsis spores responsible for shab disease, which enters through pruning wounds. Sharp tools make clean cuts that heal faster than torn or crushed tissue made by blunt blades.

Pruning young plants in their first year

In the first summer after planting, pinch out or lightly cut back the flowering shoots rather than allowing the plant to put energy into flowering. This redirects growth into establishing a broader, more branched root and shoot system. From the second year onward, follow the regular two-prune schedule.