Although lavenders are generally easy plants, requiring little or no additional watering once established, they do need annual care. Leave small, young plants unpruned for the first 12 months after planting to allow them to put on some growth, but in subsequent years cut your hedge twice a year to prevent it becoming leggy.
When to start: Late summer, after flowering, and early spring.
Time to complete: 1 hour or longer depending on hedge size.
You will need: Garden shears, household disinfectant, clippers, all-purpose liquid fertilizer.
Prune into shape
To keep your lavender plants young, bushy and healthy, cut them back in late winter or early spring. Clean your tools thoroughly and spray them with a household disinfectant before you begin work. Then, using sharp shears, cut the stems back as close as possible to the old wood.
The correct cut
Take care not to cut into old brown wood, since the plants will not reshoot from this. Shear to a few healthy leaves above the brown stems, and work systematically along the hedge, keeping it as level as possible.
In late spring or early summer, the sheared plants will grow an abundance of side shoots to create a compact, bushy hedge. To keep it neat, cut it back again after flowering in late summer: remove all the old flower heads to prevent the plants from putting their energy into making unwanted seed.