We often grow fond of lavender, but years later, it becomes old, woody, and overgrown. Here’s how to prune it to give it new life.
Pruning woody lavender facts:
Time: 3/4 years
Success rate: low
Main technique: hard pruning in thirds (⅓)
Secondary techniques: layering, cuttings, seeds
Dealing with woody lavender is more difficult than for other shrubs. Proceed carefully, and you’ll add another decade of life to your beloved lavender plant!
Can’t I just cut my lavender back to a stump?
Lavender is not a plant that easily sprouts from old wood. Other shrubs can take severe pruning and hatracking, but pruning lavender too hard can kill it.
There are two ways to rejuvenate old, woody lavender:
- hard pruning 1 third at a time
- layering stems
A different strategy is to start a new plant from the old one, through:
- preparing cuttings
- harvesting and growing from seeds
Let’s take a look at each of these techniques!
How to prune an old, woody lavender plant
The goal is to cause your lavender to send out new shoots from the base.
⚠️ Sap must still circulate ⚠️
🌿 ✔️ ❌
Important: there should still be active, leafy branches to ensure sap circulation. Buds and shoots can only sprout along stems that have leaves at their tips.
A note about patience: all methods for rejuvenating lavender require time. Your lavender will look like a work in progress for 3-4 years. It won’t look nice but it’ll be fun to see it grow!
- Monitor growth with monthly pictures (it’s a slow grower, this helps control patience).
- In spring, remove half the blooming until the shrub is well formed. Flowers slow branch growth (use the cut flowers for a lavender wand).
A grown plant has a strong, established root system, and careful pruning maximizes this advantage.
For each technique below, the first step is always a basic trimming back.
Grab a handful of branches and shorten them with sharp shears, then move on to the next handful. Stay in the “green leaf” zone: keep at least 3 in (8 cm) of leaves on live branches.
1st technique – hard prune your lavender
Over a few years, typically three or four, you can reduce the size of your lavender shrub. Since pruning all at once would kill the plant, spreading the pruning over several years is what makes it work.
- This isn’t always successful.
- Detailed guide: hard prune lavender
The idea is to group long branches into three or four batches.
- One batch is cut back to the trunk every year.
- Other batches are kept long, they’ll be pruned over the following years.
New sprouts will appear near the base, which you nurture until they replace the last of the older stems in year 3 (or 4).
2nd technique – layering
Layering is when you bury a portion of a stem under soil. Roots develop within a year. The layered stem can be cut out from the mother plant after one or two years, and replanted.
Part of the “hard pruning” technique involves keeping longer stems over a few years, so double your chances by layering them. It won’t interfere with new sprouting from the crown itself, and you’ll have more plants to go around afterwards!
3rd technique – the “donut method”
A variation of the layering method is to bury the trunk and main branches of the old lavender plant with potting mix. This is easy if the center is already bare with long branches falling over to every side.
- Spread the main branches around in a star-shaped pattern. You can layer each one to have additional plants later on. Remove shorter branches that block sunlight to the center.
- In the center, ridge soil up or use well-draining soil mix that includes gravel or clay pebbles. Cover the entire trunk area.
- Cover again with mulch.
- When new growth starts sprouting from the center area, success! Start pruning yearly as for a young plant.
- Wait for a whole year before cutting the older, larger branches off (layered ones should be ready after that year). If you cut them off too soon, you might shock and kill the lavender even though a small shoot has appeared.
With these techniques, you’ve got a reasonable chance of saving your doomed, woody lavender.
If you’re curious, below is a short overview explaining why lavender doesn’t grow back from old wood.
Why doesn’t old lavender grow back
This means you shouldn’t cut lavender back too short, since it can’t grow back.
The one in the picture above/right died the next season. It might have survived with careful watering, but chances were low.
Cutting back the entire plant all the way to the woody part is too much of a shock for the plant. Why so? It’s the result of evolution and adaptation!
Stems are engineered for drought, not regrowth
Lavender stems are very specialized.
- To lock water in, lavender stems grow watertight bark without many openings to the outside air.
- It excels at channeling sap and nutrients to and fro between roots and leaves.
- Stems store moisture during dry spells. They release it to leaves when needed.
This drought specialization came at the cost of propagation. Buds on old wood cannot sprout through the bark to turn into leaves and new stems.
Lavender deters grazing: no need to grow back
Lavender is armed against grazing. thanks to its strong-tasting essential lavender oil.
Animals like deer and rabbits hate eating lavender leaves and stems of the plant.
Since it successfully repels foraging animals, lavender doesn’t need to grow back from the stump.
Traditional options – cuttings and seeds
Instead of replacing your lavender with a new, store-bought lavender, you can propagate your existing lavender.
Cuttings – this is how professionals multiply lavender.
- You can prepare cuttings from your old lavender.
- Once they’ve grown, replace the mother plant with a cutting.
- Spring is the best time to take lavender cuttings.
- There are two ways to take lavender cuttings. Usually, “softwood tips” (green with leaves) are cut and rooted in water or soil mix. You can also take “heel cuttings“, where a young branch is torn off from a main branch. The trailing sliver of bark is where new roots form (again in soil or water).
Seeds – Some lavender varieties also go to seed.
- Collect seeds end of summer.
- Sow end of winter in a layer of soft soil mix.
- Some varieties seed profusely. For example, ‘Munstead’ (an English lavender variety) produces lots of seeds which germinate easily.
- They either don’t produce seeds, or their seeds can’t sprout.
Smart tip about old, woody lavender
Keep pruned woody stems and wrap other herbs around it to make a special “Mediterranean bouquet garni” for cooking!
Image credits: Rosalyn & Gaspard Lorthiois, own work