How hard should you prune lavender after it has finished flowering?
Lavenders benefit from annual pruning immediately after flowering to help them remain compact, dense and shapely. If you prefer to let them run riot, au naturel, they will become sprawling and woody and can sometimes take on a beautiful gnarled character but then it will be too late to change your mind as they cannot regenerate when pruned back into thick old wood. Learning just how far you can cut back lavender and have it rejuvenate is a matter of trial and error, but younger plants can definitely be cut back harder than older ones.
To test the limits, after my lavender finished flowering this August, I decided to do an experiment and prune them back much harder than usual. I had read an article saying that most people assume lavender cannot regenerate from old wood, so only give their shrubs a light pruning. Harder pruning, they explained, was not only possible, but desirable, as it would lead to more compact, dense and robust plants. So I decided to give it a go. Here is what happened…
July
The photo at the top of this post shows my white English Lavender flowering it’s heart out in the middle of July. The last flowers go over in the third week of August, when I usually take the secateurs to them and cut back into green wood, not too far, leaving the clumps like this…
They soon recover, but with such a light prune the plants increase in width by about 4 inches per year. If I carried on like this they would soon outgrow their space. In the past I had assumed that they would not tolerate heavier pruning so I had lived with this gradual bloat, but they are now approaching the limit of their space and I need to keep them under control, or remove them altogether. This set me wondering: have been over-cautious? Perhaps they can take a heavier pruning than I have given them credit for.
There is a clue, if you look closely at the stems, you can see how far back the buds go. If you cut back harder, these lower, smaller buds should grow away fine. But would there be enough to create a dense new mound of foliage? Only one way to find out…
After looking carefully for these tiny lower buds I took the secateurs to the lavenders for a second time, taking off another 2 to 3 inches of older wood. It was a bit disconcerting to see the first shrub I attacked left with almost no leaves!
The lavender in the background has only had the first light prune. The one in the foreground has had the second, much harder pruning. After completing the pruning of all four of my lavenders I mulched and watered them to help them recover.
The Results
Two Weeks
Two weeks later in late August… The tiny buds are beginning to break. There don’t seem to be many on each stem. Did I cut back too far?
Two Months
The plants are now covered in new foliage which seems to have broader leaves than usual. Although some of the heavily-pruned stems have died back and have no new shoots, there is new growth emerging deep down in the centre of the shrub coming from close to the base which I did not expect. I now think I should have been brutal with these plants from the start.
A close look reveals lots of new growth coming from the base and centre of the plants. I now wonder whether I could have cut back even harder in August, especially as these are relatively young plants. The dead stems that have not produced shoots now look unsightly and could, no doubt, be pruned out, but I will leave them until spring to help protect the new growth from the frost.
Here are the other two lavenders which are beginning to fill out reasonably well. I wonder what they will look like by the spring? Hopefully dense rounded mounds, in keeping with the other shrubs in this bed. We will have to wait and see.
[I’ll post further updates below as time goes by]
[Edit: May 2020]
The following spring
9 month’s after hard pruning
As you can see the lavenders have not only recovered from their heavy pruning, but have come back fully, producing a dense bun of foliage with plenty of flower spikes.
Update May 2021
The secret to keeping lavenders compact and domed is to prune low every year to prevent the woody base from expanding. The maintenance from here on will be to cut back to approximately the same height every year, i.e. close to the hard-prune point above.
Thanks for an informative post on lavender pruning. I have a very old/ very large lavender bush which has done well over a few years with a hard prune but the main wood stems of the bush are now very large and old and I worry prone to snapping in heavy winds. Is there a certain point when a large lavender bush would need to be removed and a new one planted when the base stems are so large?
Lavenders are considered short-lived shrubs and are generally replaced every 5 to 10 years. I knew a couple of 20+ year old ones outside a rectory which had developed beautiful gnarled stems, twisted and charming. I guess it’s a matter of taste when exactly you replace them, or you could let fate (the wind) decide for you.
Thank you for your article. The pictures and indicators are so helpful.
Glad you found it useful.
Just so you know, those lavenders are still going strong: They are nice and dense right now.
Very useful information. I’ll try this out on half my plants in the next week or two as they are still blooming after 2 harvests.
Thank you so much for sharing! My plants look like the ones you have with leaves coming on – but a lot of dead branches poking up in between. I really don’t like that! They look so messy. This spring I cut them back …and kept cutting what looked really dead – and then – oh no! Did I cut too far? I was worried for a bit, but now I see new growth at the base. I appreciate you sharing how it all went – I’m encouraged to not be quite so timid while cutting back. I love my lavenders – I don’t want to kill them but don’t want the messiness either. Yours look great in the end! I’m encouraged!
I’m glad I could help. I don’t think you need to give them such a drastic pruning every year, by the way. Mine look great two years on. Last year I gave them a much more gentle prune. The hard prune shown in the article above led to lots of dense low shoots, so I anticipate only repeating this drastic measure every three or four years.
Brilliant. Due to hospital neglected all mine so now confident I might get them back into shape. No pun intended.
Thank you for the article! I moved into a new home in May, with lots of French lavender that look like they haven’t had a trim in a very long time! I lightly pruned, but they still look pretty rough. Maybe I will try this and see how they look in the spring.
Very helpful, especially with the photos
I just read your article now, it is beginning of winter here in NJ. Can I still prune my young lavenders now or wait until next August after they bloom？ As a matter of fact my lavenders did not give a lot of flowers anyway this summer!
I wouldn’t like to say for sure.
I’m in the same boat, with several of my lavenders having missed their trim (they just kept flowering, so I kept putting it off!)
The general advice is that it’s better to leave it until spring once the frosts are over, so the plant can respond quickly.
But the general advice isn’t always the best. So, it’s your call!
Hi. Ive been working in a residential complex as a landscape engineer of 2019. I live in iran. Now its autumn. Every year i prun lavenders. But not heavy prun. light prun after flowering in the end of august. This flowers seems to aged 8 years and now some of them distored and little of them turned black and some of the bushed become as a larg wood. what do you recommond? when is the best time for heavy prunning? The amout of this lavenders is high and replacing them costs alot. Please help me. you looks very experienced.
Thanks
Hi Taban. I don’t have experience of pruning such old lavenders. The key point in my article is to look for tiny buds on the stems below the cutting point, and not to go lower than that or it is unlikely to regenerate. Remember, that lavender is essentially a short-lived shrub, so rarely lives beyond 10 to 15 years and many people replace them before then.
Thanks for sharing this process in details! This gives me some hope for the poor lavender I have pruned pretty heavily.
My friend just bought a little garden in October with LOTS of plants, including a very leggy and woody lavender. It was tilting over and didn’t look very neat. I bet the previous owner never pruned it.
After reading online I decided to give it a shot anyway and heavy prune…all down but not lower than still having small leaves peaking from the sides of the branches. I saved lots of cuttings hoping they would root in water at home, but that has not really worked. After all its winter and dark times. … Must be the reason.
So I hope the big plant survives. I’m very curious how it willl turn out. Despite stilll being cold, it looks like it’s growing some fresh green leaves, so I’m still positive.
Well done! It sounds like it’s a much older plant than mine, but hopefully those little leaves will sprout int he spring. Fingers crossed!
Thanks so much for sharing your experience of pruning lavender. This year I pruned mine back harder than I ever have before, and every glance at them makes me wince. However, your article with its very helpful pictures put me at ease, and now I feel more optimistic that they’ll revive with an improved growth habit, which was my goal for doing a harder prune. Thanks again and happy gardening!
Glad you found it helpful. As long as your lavenders are not too old and woody you should be fine.
It’s The middle of May in Southwest Michigan didn’t cut my lavender last year and one of them died. The other ones are turning green but it’s leggy and I would like to cut it back now. Is it too late to prune them back?
Hi Connie
As for pruning yours… It’s not an ideal time, as the plant will have already started investing energy in new shoots, but you might get away with it if you are not too harsh.
Look at the part of the lavender shrub you intend to keep. If it has plenty of new shoots then cutting back the rest should be OK.
Lavenders are not particularly hardy. Mine have been hit hard this year by the long cold spring. They are only just sprouting now, but very lop-sided. I’m thinking about replacing them. Sometimes it’s the better option.