With this trim, your lavender hedge will last nearly twice as long.

A purple cushion of flowers in summer, grey‑green shrubs in winter - that is how many people picture lavender. In reality, it often ends up as little more than dry twiggy stems that look tired after just a few years. The problem is usually not the climate or the soil, but how - or whether - the plant is pruned at all. If you cut lavender back deliberately and at the right moment, you can almost double how long it thrives.

Why lavender ages so quickly without pruning

Lavender is not a typical herbaceous perennial; it is a subshrub. In other words, it rapidly forms hard, brown, woody growth at the base, while the younger, green shoots sit above - and that is where the trouble begins.

The old woody section produces hardly any new buds. If a bush is left unpruned for years, or is cut back inconsistently with no plan, the following tends to happen: the centre opens up, the plant collapses outwards, and it starts to resemble a dry, brittle broom. Then, when people panic and cut too far back into the wood, they often kill off entire shoots.

"Lavender that is cut back each year in the green growth can stay vigorous for up to two decades - neglected plants often die after less than ten years."

Regular pruning keeps the shrub youthful: it pushes out fresh side shoots, stays compact, and forms far more flower spikes because light can reach the whole plant.

The two most important pruning times each year

Getting the timing right matters almost as much as the method. Many gardeners hesitate because they fear cutting “too early” or “too late” - and end up not cutting at all. Lavender will make you pay for that.

Main cut after flowering (lavender)

The key pruning window is immediately after the main flowering period. Depending on where you live, that is roughly from late August to late September. At that point most blooms have faded, but the plant still has enough energy in the shoots to respond well to pruning.

• Aim: remove spent flowers, restore the shape, and keep the shrub compact.
• Method: cut only in the green, leafy growth, shortening the fresh shoots by about one third.

Second cut in late winter

A second, optional session falls between February and March, before sap flow really ramps up. This is mainly for tidying and refining the shape.

• In mild areas: prune normally after flowering, then do a light re-shape in late winter while buds are still tight to the stems.
• In exposed locations and upland areas: in autumn, only do a rough clean-up by removing the old flower stems. The proper shaping and maintenance cut follows in March on a dry, frost-free day.

The calendar is only a guide. What matters is what you see: if the shoots are still soft and green, pruning works well. If you cut into dead brown wood, the shrub will barely respond.

How to prune lavender properly - step by step

Before you start, quickly check your tools. Sharp, clean equipment prevents crushed stems and lowers the risk of disease.

• Prepare your tools: sharpen and disinfect the shears.
• Choose dry conditions: no rain and no frost - cuts dry out quickly in good weather.
• Set a safety line: identify the lowest ring of green leaves. Never cut below it.
• Remove spent flowers: snip flower stalks just above the first pair of leaves.
• Reduce the green growth: trim the fresh shoots overall by around one third.
• Finish the shape: the plant should look like a slightly flattened cushion - rounded, not boxy.

"The invisible “safety line” - the last closed ring of green leaves - decides whether your lavender comes back or goes bare."

Caution: these pruning mistakes will ruin your lavender

Lavender can cope with a lot - but not everything. Some well-intended cuts mean entire sections will never grow again.

• Severe cut into brown wood: if you cut deep into fully woody growth, you risk dead branches, because there are few (or no) dormant buds left there.
• Late, hard spring pruning: once the plant is in strong sap flow, a heavy cutback can cause shoots to dry out.
• No pruning for years: the shrub grows tall and unstable, splits apart, and eventually becomes very difficult to rescue.

With very old plants, only a gradual approach is sensible: over one to three years, remove a few of the oldest branches bit by bit rather than shortening everything at once. If there is genuinely no green regrowth left at the base, rejuvenation is rarely worthwhile. In that case, it is better to take cuttings and raise young replacements.

Caring correctly for young, mature and old lavender plants

Shape young plants firmly

In the first years, lavender tolerates much stronger cutting. If you shorten young shrubs by up to half, you encourage good branching. That creates dense, sturdy bushes that are easier to maintain later.

Maintain mature shrubs more gently

On established plants - whether traditional English lavender, lavandin, or French (butterfly) lavender - pruning should be more cautious. Always leave 3–5 cm of green, leafy shoots standing. This preserves enough reserve to form new side growth.

Rejuvenate older specimens in stages

Very old shrubs with a heavily woody centre should be renewed step by step. Each year, only a few of the oldest branches are removed. At the same time, check whether young green shoots are still appearing at the base. If they are not, the plant has passed its peak - then starting again with cuttings taken from the most vigorous shoots makes more sense.

Why this pruning works so well

The underlying principle is straightforward: lavender remains active in its young, green zones. If you consistently cut only there, you prompt the plant to keep producing new shoots from semi‑mature growth. That brings several benefits:

• denser, more stable cushions
• more flowers over many years
• a much longer lifespan across the whole bed
• fewer breaks caused by wind or snow

Another advantage is that the cushion shape lets light reach all parts of the plant; foliage dries more quickly, so fungal problems find it harder to take hold.

Practical extras: position, varieties and combinations

Even perfect pruning will not achieve much if the site and general care are wrong. Lavender needs full sun, free‑draining, fairly lean soil, and it hates waterlogging. A thin layer of gravel around the plants helps prevent soil splash and also enhances the look.

If you feed it, do so sparingly. Overly rich nutrients encourage lots of leafy growth but fewer flowers, and they reduce winter hardiness. If your soil is extremely sandy, it is better to work in a very thin layer of well‑rotted compost once a year.

In mixed borders, lavender looks particularly balanced alongside plants with similar needs: catmint, sage, thyme, or low-growing roses. A consistent post‑flowering cut keeps the whole bed looking neat and structured.

If you garden in very cold areas, you can lightly cover the base of the shrubs with brushwood in winter. That does not replace good pruning, but it does shield the woody parts from severe frost. Remove the cover again in spring so the young shoots receive enough light.

With the right cut at the right time, a clear eye on the green “safety line”, and a suitable site, lavender stays for many years what it ought to be: a fragrant, living cushion of flowers rather than a dull heap of grey sticks.