After six to ten years, a lavender becomes a mass of long woody stems with green growth only at the tips. Hard pruning can restore that neat round mound, but only if the work is spread over three or four years: cut the whole plant back in one go and it dies.
| Success rate | rather low |
|---|---|
| Difficulty | high |
| Time | 3 to 4 years |
| Season | spring |
Cutting lavender back hard in one go will kill the plant. You have to spread this work over three years.
→ Avoid this with regular lavender maintenance pruning
Usually, old lavender is replaced. However, many of us grow attached to the plants we care for. Perhaps they were a gift, or were planted by a person we cherish. We’re loathe to just pull it out without even trying!
The plant might not survive. This isn’t due to any particular mistake or bad luck. It’s just that lavender doesn’t cope with hard pruning well.
Staging the hard pruning over three years (or even four) makes it easier on the plant.
The goal is to strike a delicate balance.
You can trigger new shoots from around the base by following these steps:
Hard pruning an old lavender is not one job but a sequence, each year taking away a share of the old wood while the new shoots build up. Here is what happens at each stage.
| Stage | Woody stems cut back to the trunk | Remaining growth | What to expect |
|---|---|---|---|
| Year 1 | One stem in three | Tips shortened to 2–3 inches (7–10 cm) of green leaves, 4–5 pairs left | Holes in the shrub let light reach the centre |
| Year 2 | Half of the remaining older, leggy shoots | New young shoots trimmed to half their new growth | A few slow-growing shoots emerge from the old base |
| Year 3 | All remaining old, woody stems | Back to regular yearly trimming | The previous year’s shoots have branched out |
| Four-year option | One stem in four each year | Same as above, spread out further | Softer on the plant, less shock |
Whichever pace you choose, the work is done in spring and the old wood leaves in batches, never all at once.
Keep pinching or cutting the tips off these shoots every time they reach four or five new pairs of leaves.
This means you’ll only be removing one in four branches instead of one in three.
We’ve seen that one of difficulties is that young branch buds can’t appear on old wood.
If you lightly wound the trunk or large branches near the base, by scraping a very thin layer of old bark away, the plant will heal the wound.
In doing so, it will also produce new buds and branches near that spot, if it gets light.
You can also layer lavender.
Layering also takes two or three years. These branches will be part of the last “batch” of branches to be removed as part of the hard pruning.
Hard pruning involves cutting pieces off your lavender plant.
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Make lots of cuttings from the stems and twigs you collect upon pruning. You’ll have the joy of having even more plants to grow and give away!
Hard pruning of lavender should be performed in spring and takes 3 to 4 years to complete. The staged approach spreads the work over multiple years to avoid killing the plant, with one-third of woody branches cut back to the trunk each year.
Cutting all woody stems at once stops sap circulation throughout the plant. New buds and sprouts cannot pull nutrients and water up from the roots when only woody stems remain, causing them to die off and triggering severe pruning shock.
The success rate of hard pruning lavender is rather low, and the difficulty is high. However, spreading the work over four years instead of three, scarring old wood to promote new growth, and layering branches can improve the chances of successfully rejuvenating an old woody plant.
You can prepare cuttings from the stems and twigs collected during the hard pruning process. Additionally, you can layer two or three of the longest branches by fastening them to the ground to root, which takes two to three years and produces new plants while rejuvenating the original plant.
Lightly scarring the trunk or large branches by scraping away a thin layer of bark to reveal the green cambium layer underneath encourages new buds and branches to form. Make several lengthwise cuts (1-3 cm long, 5mm wide maximum) on different sides, and ensure the scarred areas receive adequate light by pruning surrounding branches.
