Updated: Sep 13, 2020
Lavender is evergreen, scented, pollinator-friendly and ideal for a low maintenance garden design. You rarely need to water, feed or stake it. It only needs one thing from you: an annual prune. Here's how to do it right.
When to prune
Most kinds of lavender have finished flowering by the end of August. When the flowers have turned grey, as shown here, it's time to prune.
Why timing is important
You want to cut off the spent flowers before the plant wastes energy setting seed
If you prune in August/ early September the plant will put on new growth and look smart throughout the winter
The new growth will be hardy by the time the frosts come
Don't prune half-hardy lavandula stoechas (i.e. French butterfly lavender with the 'ears') any later than August. If you're reading this in September... you've probably missed the moment.
How to prune
Use clean, sharp secateurs or sturdy scissors.
First, gather small handfuls of flower-stems and cut them off at the bottom of the stalk.
Next, trim the plant to shape. Cut down only as far as the lowest green shoots.
Don’t cut deeper as older woody stems don't grow new leaves: you will end up with a patchy, uneven plant.
When you’ve finished, there should be enough leaves to make the plant look 'covered'. The middle section of this hedge has been pruned, the closest and furthest ends haven't yet: you can see the amount to remove! By the end of the September it will all be green again.
If you planted your lavender this year, the same rules apply. It may seem a bit mean, but firm, formative pruning will encourage your young lavender to bush out. You're mature plant won’t end up with bare legs, or a mop on stilts.
Enjoy your annual trim. It’s one of the nicest-smelling jobs in the garden!