When and how to prune lavender

Keep your lavender looking its best.

Lavender is one of my go-to staples in the garden. Not only does it have beautifully fragrant flowers and aromatic foliage, but it is also drought-tolerant and the perfect choice for our increasingly hot, dry summers. And as a bonus, its silvery grey leaves also look pretty when it’s not flowering. 

But to get the most out of this beautiful shrub and its array of purple, blue, pink or white flowers, it needs to be pruned at the right time to help it thrive. From personal experience, when I’ve left my own lavender unpruned, it’s led to a woody base that splits and looks unsightly. So a little pruning will go a long way to extend the life of your lavender and keep it in top condition.  

Here’s what the top gardening experts advise to keep lavender looking luscious. 

Lavender in full bloom in the Cherry Garden at the Ham House and Garden, National TrustCredit: © NTI/Chris Davies
The Cherry Garden at the National Trust’s Ham House and Garden on the River Thames in Richmond features a mass of lavender planting

Why prune lavender?

It keeps it compact and healthy

Saga Exceptional spoke to Guy Barter, chief horticulturist at the RHS, to ask why lavender needs pruning. “Left to its own devices, lavender gets scraggly after just a few years, with woody stems that produce less and less leaf and flower,” says Barter. “Pruning delays this and keeps the bush looking attractive for many years.” 

Pruning can certainly extend the life span of a plant, according to the Thompson & Morgan website: “When properly pruned, some varieties of lavender can last up to 20 years. Left untouched, it soon becomes shapeless and woody, with few flowers and long, bare stems.  

“If you don’t prune, you’ll get a much wilder looking plant – it will become unruly, with gaps and patches inside,” says John Myers, head gardener at the  National Trust’s Ham House and Garden in Richmond. “If you’re looking for a more formal shape or to keep the plant within certain boundaries,” he adds, “it’s best to prune.” 

Apart from keeping your lavender in shape, Myers says that pruning will also help to encourage good flowering next year – a must for those gardeners who like to harvest and dry the lavender buds.  

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When to prune lavender

Lavender is ready for pruning during August

While some gardeners suggest pruning in mid-spring before growth begins, Barter says: “Pruning after the flowers have finished in late summer works well for us at RHS Garden Wisely.” 

Myers agrees, telling us: “We start to prune around August once the flowers have finished.”  

Pruning at this time has a double advantage if the flowers are past their best, but not brown. “You can cut and save your flowers for pot pourri or for putting into bunches whilst pruning at the same time,” says Myers. 

Bee on Lavandula angustifolia SuperBlue.Credit: © Jonathan Buckley
Lavender is a great choice for any size garden and provides rich pollen and nectar for bees and butterflies over the summer months

Tender lavender can be treated slightly differently and will need deadheading over the summer but will only need pruning if it is out of shape. 

Lavandula stoechas 'Sancho Panza' - French or Spanish lavenderCredit: © Jonathan Buckley
Lavandula stoechas ‘Sancho Panza’ is a half-hardy specimen that can be trimmed back after flowering or in the early spring

While I’m sure we’d all prefer to be described as ‘leggy’ rather than ‘compact’, for lavenders, their beauty is more noticeable when they’re trimmed to a neat shape.  

How to prune lavender

Cut back and shape to invigorate new growth

I find pruning lavender to be therapeutic – the fragrance is instantly relaxing, inducing a sense of calm to a gardening chore. And although pruning lavender isn’t tricky, it’s worth gaining a few tips from the experts.

1. Choose your cutting tool

Barter suggests using a sharp pair of secateurs or snips, although he does say that “some busy, but steady-handed and bold gardeners use shears or even hedge trimmers.” We’d recommend our best buy secateurs for the job, by Draper.

Your cutting tool will also depend on the size of your plant. If your lavender is small, you’ll want to opt for some garden snips or secateurs, but if you’ve grown your lavender into a hedge, you’ll need something larger, like shears. 

To guarantee a good clean, healthy cut on the plants, it’s worth sterilising your cutting tool of choice before use. Simply clean them with rubbing alcohol or bleach, before rinsing off and drying.

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2. Look for visible signs that the plant is ready to prune

Although our experts have advised that August is a good time to prune lavender, you can look out for the visible signs. Wait until the flowers are past their best, but they don’t need to be brown. 

3. Consider what you want to achieve

Before you start to prune, Myers suggests thinking about what you want to achieve: “Are you trying to keep the plant small, or do you want to create a certain shape?”  

4. Get pruning

“Start by cutting off the old flower stalks,” says Myers, “and as long as you’re cutting into the soft wood, it’s quite easy to cut.”  

You can then start to give the plant a nice shape by removing the leggy branches. This will help the plant appear fuller and will leave it in a good place to develop a new flush of flowers next year.  

Why cut the soft wood rather than the old wood? 

You’ll get the best result if you cut into the soft wood rather than the old wood, as this way you’ll be leaving new shoots that will bud and make more growth and flowers next year. Barter recommends leaving 25mm (one inch) of new growth when pruning. 

However, if you do cut into the old wood, it’s not a disaster. “You’ll get a bit of a gap and it won’t necessarily grow back as quickly as the soft growth,” explains Myers. And it may also limit the flowering the following year. 

5. Going for a professional finish

Although most of us won’t have the extensive area of lavender that Myers takes care of at Ham House and Garden, we can still learn a trick or two from how he shapes his plants.   

To create a neat, mounded shape, Myers uses a template made of two lengths of wire cut to an equal length. The wire is shaped into two arches and joined to make four quarters at 90°.  

“We place the template into the plant and then cut it in quarter sections,” he explains, “meaning we end up with a lovely mound of lavender.” 

Is it wise to prune new lavender? 

“I’d avoid pruning it during its first year or so to let it settle in.” says Myers. “Allow it to get to the size you want and then give it a prune to tidy it up.” 

Know your lavender

Is your lavender hardy, half-hardy or tender?

Before grabbing your secateurs, snips or shears, you’ll need to check which variety of lavender is growing in your garden. English lavender, including Lavandula angustifolia and Lavandula x intermedia, is the hardiest variety and needs to be pruned the most. Whereas, French lavender, including Lavandula stoechas, is half-hardy and requires a softer touch.

Finally, tender lavenders, such as Lavandula pinnata – which are not frost-hardy and are best planted in pots and brought into a greenhouse or a conservatory to survive the winter – are more likely to need deadheading rather than a hard prune.  

Myers says that most of the lavender varieties we commonly grow are hardy, examples of which are Lavandula angustifolia ‘Hidcote’ and Lavandula angustifolia ‘Munstead’, which he grows himself at Ham House and Garden.  

What does French lavender look like?

French lavender can be identified by its small tufty purple flowers, which are like butterflies. It is less hardy and will need replacing after around five years. 

French Lavender with distinguishing 'ears'Credit: Janaph
French lavender is less hardy than English lavender and can be identified by its distinguishing ‘ears’

Garden expert Sarah Raven suggests that the half-hardy, French lavender, Lavandula stoechas ‘Sancho Panza’, works well in a variety of different gardens. “It’s an excellent seed-grown lavender, it’s super-early to flower and lasts from May right through summer.” She adds: “Trim it back after flowering or in the following spring to maintain a compact habitat, which will prevent it from becoming overgrown.” 

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Camilla Sharman

Written by Camilla Sharman she/her

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With her 30 years of experience, Camilla Sharman has covered a wide range of sectors within the business and consumer industries both as a feature, content, and freelance writer.  As a business journalist, Camilla has researched articles for many different sectors from the jewellery industry to finance and tech, charities, and the arts. Whatever she’s covered, she enjoys delving deep and learning the ins and out of different topics, then conveying her research within engaging content that informs the reader.