The Simple Pruning Tip That Keeps Your Lavender Full & Healthy

Lavender is a wonderful plant to have in any garden. In addition to its beautiful purple hue and delicate fragrance, this herb has many uses: it attracts pollinators, repels insects, and can be dried and used as a relaxing tea or essential oil. If you have incorporated lavender into your landscape, it's important to know when and how to prune these pretty perennials to keep them healthy and encourage more blooms. One simple guideline you can use is the 8-8-8 rule, which can help ensure you're pruning properly and at the right time.

The idea behind the 8-8-8 rule is that on the 8th day of the 8th month of the year (August), trim the lavender back by 8 inches. A different variation of the rule leaves out the 8 inches but says to prune at 8 a.m. on the same day. While the 8-8-8 rule is not intended to be strictly followed, it acts as a useful reminder of when and how much you should be pruning lavender. 

The reasoning behind the timing is that early August is typically late enough in the growing season that the flowering cycle has ended — the flowers have turned gray — and the pollinators have gone. It's likely early enough, however, that the soil is still warm, which encourages regrowth, and the plant has some time to recoup before the cold weather rolls in. Because of regional variations in climate, the ideal timing for pruning will depend on your location and where your plants are in their growth cycle. 

While the 8-8-8 rule suggests cutting back 8 inches, that should also be taken as a general guideline, rather than a strict rule. How aggressively you should prune will depend on the specific type of lavender and how much growth the particular plant has produced. While hard pruning — cutting back a large portion of the stems – is generally recommended, you need to be careful how far down you go. A mistake to avoid while pruning is clipping the woody part of the plant, as doing so will prevent future growth. Instead, make sure you're only trimming new growth approximately 2 inches above the woody stems. While you don't want to cut too far down, at a minimum, you should aim to cut the stems by at least ⅓ of their length.  

In addition to keeping your lavender plants healthy and full, yearly pruning will also prevent them from becoming scraggly. The goal should be to shape the plant into a smooth, rounded dome when pruning. This can be done using clean, sharp shears or pruners. If done in the right way and at the right time, pruning will keep your plants looking beautiful while encouraging strong new growth.