How to Prune woolly lavender?
Shorten flowered shoots to about 1.5–2.5 cm from the previous year's growth. If flowering is on last year's growth, prune after flowering; if on current-year growth, prune the following early to mid-spring.

woolly lavender · Lavandula lanata
Grow in moderately fertile soil in full sun. Overwinter in frost free conditions and on the dry side. See lavender cultivation for further advice
Shorten flowered shoots to about 1.5–2.5 cm from the previous year's growth. If flowering is on last year's growth, prune after flowering; if on current-year growth, prune the following early to mid-spring.