Pruning lavender for next year’s growth
It’s a question I get asked a lot, when, why & how to prune Lavender & have also seen some leggy, woody Lavender on my visits that has suffered from no annual trimming. It’s all about ensuring that this perennial plant thrives year after year. While some plants can go without pruning, lavender likely will refuse to flower next summer if you don't prune it (and, let's be honest, it's all about the fragrant flowers with lavender). Lavender plants also tend to get leggy and misshaped if not pruned, so you'll want to make sure you remember to do it.
When to prune lavender?
As soon as it's finished flowering, but before the flowers have completely dried out. You want at least some new growth to appear before the plant goes dormant for winter, so do it sooner than later. Some varieties of lavender finish flowering earlier ('Melissa Lilac', for example), so prune them earlier in August, or even in July.
valuable tip for pruning lavender, don't cut so hard that there are no green shoots remaining, as lavender may not regrow from just the woody stems. leave a few green shoots to encourage a healthy new growth next year.
“I've pruned my lavender, but it's still not flowering”
If you pruned your lavender, but it still has failed to flower, the most likely reason is that the lavender plant isn't getting enough sun. Lavender loves full sun, and lots of it – at least six hours a day for optimal flowering. South- or west-facing gardens or windowsills are best for it; in a north-facing garden, lavender is likely to just remain green and not produce any flowers. Very wet summers without much sun may also reduce the amount of blooms your lavender plant produces.