Prune lavender in March for abundant summer flowers

Anyone planting lavender dreams of fragrant purple cushions buzzing with bees. Yet summer often brings sparse, bare stems with only a handful of meagre flowers at their tips. The difference between disappointment and a carpet of blooms is decided sooner than many people realise: in March, with one very straightforward prune.

Why you should prune your lavender in March

Lavender is a subshrub. In other words, it becomes woody at the base year after year while producing soft, green foliage at the top. Without pruning at the right time, the greenery gradually moves further upwards, the shoots become longer and the base turns bare. Eventually, all that remains are brown, stick-like stems carrying very few flowers.

“A light early prune in March directs the plant’s energy into fresh, low shoots – precisely where most of the flowers will later form.”

Gardening professionals point out that the abundance of lavender flowers in summer is determined as early as the start of spring. Pruning too late shortens the flowering period and risks leaving the shrub sluggish at the start of the season.

March offers two key benefits: the hardest frosts have generally passed, while new growth has not yet properly begun. The shrub can therefore put its energy into plenty of new side shoots rather than a small number of long, whip-like stems.

What happens if you postpone pruning

If you do not pick up the secateurs until late spring, you effectively remove part of lavender’s first flush of flowers. The plant then needs longer to produce new shoots, flowering is delayed and the overall display is often less impressive.

Skipping pruning altogether is even less helpful. The shrub slowly ages, becomes heavily woody and is increasingly difficult to rejuvenate over the years. Many amateur gardeners eventually remove these bushes in frustration, even though a simple March prune could have kept them well shaped for years.

How to prune lavender correctly in March

The essential rule for spring pruning is not to cut into old wood. Cutting back too boldly can leave bare patches that are unlikely to shoot again.

The perfect lavender prune in three steps

• Step 1: Examine the structure of the shoots
  Choose a typical stem and inspect it closely. Its lower section is brown and hard, forming the woody base; further up, it becomes green and soft, where leaves or fresh buds are found.

• Step 2: Choose the cutting point
  Position the secateurs in the green section, roughly five to seven centimetres above the hard wood. Always cut where there are leaves or dormant buds, never into completely bare wood.

• Step 3: Shape the plant
  Work around the entire shrub, creating a rounded, gently flattened lavender mound. You can cut the outer stems a little shorter than those in the centre to achieve an attractive cushion shape.

Use sharp, clean garden secateurs to make smooth cuts and prevent diseases entering through damaged stems. Remove dead, frost-damaged or diseased branches completely, cutting back to the point where healthy wood becomes visible again.

“The rule for March is: trim gently, restore the shape and cut green wood only – save radical pruning until after flowering.”

Light shaping now, harder pruning after flowering

The March prune is essentially a cosmetic treatment. Its purpose is to create order and shape while encouraging plenty of fresh shoots. The genuinely vigorous cut follows once the main summer flowering period has ended, usually in August.

At that point, you can shorten the spent flower stems more firmly, again remaining within the green growth. This keeps the shrub compact even as it ages and often encourages a second, lighter flush of flowers in late summer.

The most common lavender-pruning mistakes

Many lavender bushes look tired because the same errors are repeatedly made. Avoiding them means you are already halfway to success.

• Pruning too late: The first cut is not made until May or June, so the plant flowers less strongly and becomes woody more quickly.
• Cutting into old wood: Cutting deeply into brown, bare sections often results in dead, grey stumps.
• Not pruning at all: Fear of making a mistake leads to no pruning whatsoever. This speeds up woodiness and makes the bushes more prone to snapping.
• Using nitrogen fertiliser: Heavy feeding produces soft, unstable green growth but little fragrance or flowering, while also making the shrub more susceptible to disease.
• Choosing the wrong site: Shade and wet soil quickly leave lavender bare and cause it to rot, regardless of how well it is pruned.

Lavender varieties that respond especially well to a March prune

Modern cultivars reward proper care with flowers lasting for months. Particularly hardy are the varieties known as lavandins, which are crosses between different lavender species. One frequently recommended example is Lavandula x intermedia ‘Phenomenal’.

Feature	Description
Height / spread	Around 60–70 centimetres, forming compact cushions
Flower colour	Blue-violet, densely packed on long stems
Fragrance	Strong, classic lavender scent
Care	Water very little, avoid high-nitrogen fertiliser, prune in March and after flowering

Traditional “English lavender” and heat-loving varieties with tufted flowers, often sold as “French lavender”, also benefit from this schedule: a light shaping prune in March followed by a stronger cut after the main flowering period.

How to create the perfect conditions for clouds of flowers

Even the best pruning will achieve little if the location is unsuitable. Lavender originates from sparse, sunny regions and tolerates our typically wet winters only to a limited extent.

Lavender site checklist

• Light: At least six hours of sunshine daily; the more sun it receives, the more fragrant the flowers.
• Soil: Free-draining, relatively poor and slightly sandy or gravelly. Improve heavy clay soils with sand or horticultural grit.
• Watering: Water regularly only during the first few weeks after planting, then use a light hand. Avoid waterlogging at all costs.
• Feeding: Do not use standard flower fertiliser. It is better not to feed at all, or to apply a potassium-rich garden fertiliser only very sparingly.

If your soil is heavy, plant lavender in raised beds, dry-stone walls or large containers. Container-grown plants particularly benefit from a March prune, as their shoots can otherwise quickly grow lopsided and flop over.

Why pruning matters especially after a wet winter

Damp, mild winters often cause lavender to rot from the base or suffer partial frost damage. In spring, plants can look ragged, with brown tips and grey, dead sections.

This is exactly when timely March pruning helps: it removes damaged growth before fungal diseases can spread and stimulates healthy buds to grow anew. Even shrubs that have had a difficult time can recover surprisingly well in this way.

“A few targeted cuts in March are the cheapest ‘insurance’ for your lavender – they take just ten minutes but deliver months of flowers.”

Combine lavender cleverly for more fragrance and benefits

Lavender does more than look attractive: it adds structure to beds and its scent can often deter unwanted insects. Thoughtful combinations offer even more benefits:

• With roses: A classic pairing. Lavender softens formal rose beds, attracts pollinators and may help keep aphids slightly at bay.
• With Mediterranean herbs: Rosemary, thyme, sage and lavender enjoy similar conditions. Planting them together makes care easier to manage.
• Along paths: Regularly trimmed lavender creates a fragrant, low hedge beside garden paths.
• In a family garden: Children can gather and dry the flowers to make scented sachets, while the hardy shrubs can tolerate the occasional clumsy touch.

One point matters in mixed plantings: keep an eye on growth habit. Regular shaping in March keeps plants low enough that they do not overwhelm their neighbours and ensures each one receives sufficient light.

How to tell when your lavender cannot be saved

Some shrubs are so old and woody that even the best March prune cannot rejuvenate them. Typical signs include:

• More than two thirds of the plant consists of bare, grey-brown wood.
• New shoots appear only on a few of the outermost tips.
• After a moderate prune, the lavender produces little or no new growth in spring.

In this case, starting again is often worthwhile. The advantage is that modern varieties grow quickly, and with the correct pruning routine you can have dense, fragrant cushions again after only one or two years.

Picking up the secateurs in March sets the course for summer. A few clear principles – cut green wood only, create a cushion shape and delay radical work until after flowering – are enough to ensure lavender does not become a woody problem plant, but instead turns into what many gardeners want: a reliable, purple long-flowering feature by the front door.