Prune lavender bushes by selectively cutting two to three growth nodes off of the fastest growing shoots to create the desired size and shape. Next, remove dead and dying branches, and cut dried flowers. Gardeners should prune lavender with clean pruning tools at two intervals in spring after the plants emerge from winter dormancy.
Gardeners can prune dead flowers and dead branches from lavender bushes at any time of the year. The optimal time to prune and shape lavender bushes is in spring. When lavender first begins to generate new growth, prune the shrub by removing dead branches killed by cold temperatures over the winter. To promote optimal flowering, do not cutting live branches at this interval.
After the first flush of flowers has dried, gardeners should first remove dead flower stalks. Next, establish the shape of the shrub by cutting select vigorous shoots and cutting two to three leaf nodes of each shoot. By methodically pruning each long shoot over the entire plant, gardeners can promote dense growth in the shrub canopy and maintain a uniform shape.
When pruning lavender, it is important to avoid making cuts in the fall or winter. Pruning in these seasons stimulates new growth and saps the plant's energy reserves. The new growth does not usually survive the cold temperatures of winter. Gardeners should also avoid "renewal pruning," a term referring to the practice of pruning all stems to ground level. Renewal pruning can potentially remove the plant's growing points and kill the plant.