Pruning is an important part of the lavender growing process, keeping plants healthy and productive, since it helps to prevent plants from becoming too woody and splitting open at the base. Generally, lavender plants live for 8-10 years, but a lavender-growing friend of mine still has most of her original plants from 16 years ago, and she swears it’s because she diligently prunes her plants back every year.
When to prune your lavender is your first consideration. The end of Summer or Spring are the two times to prune lavender. To decide which will work for you, it helps to think about the goal of pruning. In the late Summer, pruning shapes the plant and removes any dead branches that could weaken the plant during the Winter. Just don't prune after the end of Summer since pruning stimulates new growth and any cold snap would kill the new growth and weaken the plant, making it more difficult for the plant to survive the winter. Pruning in the Spring after danger of any hard frosts is your other option, again removing any dead branches but also stimulating new growth so your plants get a jump start on the season.
Which do I prefer? I find that as I harvest in summer, I am also doing a light pruning. I harvest the full length of the stem, often with a few leaves attached, and this deep harvest helps to keep the plants’ shape and stimulate growth so that I will often get another bloom later in the Summer or Fall. So I've started awaiting until Spring to do my deeper pruning to wake my plants up and get them growing again.
So how does one prune lavender? The rule of thumb is to remove about ⅓ of the green growth, shaping the plant into a nice round mound as you do so. You want to avoid cutting into the woody growth of the plant unless absolutely necessary (if the plant hasn’t been pruned for a while and is looking very woody instead of bushy). For a deeper pruning, find the woody area and cut two inches above that. If you are going to cut into the woody area, do so only during the Spring when the plant has time to recover in milder weather.
As for pruning tools, if you have just a few plants, then clippers work just fine, but when you’re pruning more than just a few plants, I have found that a cordless hedge trimmer works really well.
And Hey! An added benefit of pruning is that it provides lots of material for plant propagation! Because who doesn't want free plants?
Little Lavender Shop 108 S College Ste C Newberg, OR 97132 Hours: Wed-Sun 11-6
Little Lavender Farm 11011 NE Paren Springs Rd Dundee, Oregon 97115 (Farm is open by appointment and for Exclusive Events Only)