Good lavender after flowering care means cutting back your spent blooms and giving your plants a light shape at the same time. This keeps them compact and can trigger a second round of flowers in many types. Your timing depends on your climate zone.
In my experience, harvesting faded flower spikes each July works great for drying and crafts. While I gather the blooms, I also trim my plants into neat mounds. This approach saves you time and gives you bundles of fragrant stems for sachets. Nothing goes to waste when you plan your pruning this way.
When you remove spent flowers through lavender deadheading, you change how your plant uses its energy. Flowers left on the stem will form seeds, which takes a lot of resources from your lavender. Cutting them off redirects that energy to root growth and new foliage instead.
University of Illinois Extension says you should remove one-third to one-half of your plant after blooming ends. This shapes your lavender while leaving enough foliage for good health. Some varieties will push out a smaller second flush of flowers in late summer.
Your method for post-bloom lavender maintenance should be simple but careful. Grab a handful of stems and cut them about two inches above the woody base. Keep your cuts above any brown wood and leave plenty of gray-green foliage on each plant.
In cold zones 5 and 6, you must finish all post-bloom cutting by mid-August. New growth needs about six weeks to harden off before frost hits. If you cut later, you risk tender shoots that will die in winter and damage the stems below them.
If you garden in warmer zones 7 through 9, you can wait until September for this task. Your longer growing season gives plants more time to bounce back. I have friends in these areas who get a third bloom by doing a lighter trim after their second flowering ends.
Save your spent blooms even if they look past their prime because the flowers hold their scent for months when dried right. I tie small bunches with string and hang them upside down in my garage. After two weeks you can use them for sachets, potpourri, or homemade gifts.
When I first started growing lavender, I left the old flowers on too long and my plants got woody and sparse. Now I set a calendar reminder for early July to start this task. You will thank yourself later for staying on top of post-bloom care during the busy summer months.
Read the full article: How to Prune Lavender Plants for Better Growth
