Knowing when to prune rosemary, and how exactly to go about it, is important if you're growing it in your garden. A regular trim prevents these flowering shrubs from becoming unruly. But, with the wrong timing and technique, you may risk damaging your plant.
Growing rosemary fits alongside the vegetable garden trend perfectly, as the evergreen herb is a versatile ingredient in the kitchen. It also works beautifully in a Mediterranean-style garden, and the blue (or sometimes pink) spring flowers are a magnet for bees.
Pruning keeps rosemary looking tidy, but don't start snipping away at it with wild abandon. Just like when pruning hydrangeas, a bit of know-how and some good quality tools are needed. Below, the experts share their tips to help you get the best results, including the key mistakes to avoid.
How and when to prune rosemary, according to gardening professionals
Don't forget that healthy rosemary cuttings can be used fresh or dried in a myriad of recipes, from roast potatoes to homemade bread. You can even use a sprig to garnish a low-calorie cocktail.
When to prune rosemary
In terms of when to prune rosemary, Craig Wilson of Gardener's Dream recommends late spring or early summer, just after it flowers. This gives new growth plenty of time to establish before frosts set in later in the year. Not only this, but he notes how the cuttings have the best flavour at this time if you plan to use them in the kitchen.
If you miss this window and want to trim it back later in the growing season, aim to do so at least six weeks before winter weather sets in.
The time of day matters, too. The Crocus plant doctor recommends ticking off the task in the morning, "when the plant is well-hydrated and the sun is less intense." This is also a good time to prune tomatoes after they've been watered.
How to prune rosemary
Claire Hooper of Hillier Garden Centres recommends cutting rosemary back by around a third. This is similar to pruning roses.
She suggests focusing on cutting back the tips of the branches, aiming to keep the overall shape bushy and rounded. Avoid cutting into the woody, leafless stems. Any dead or diseased parts also need to be removed to help the plant focus its energy into the healthy growth, she adds.
Top tip: The Crocus plant doctor recommends making cuts just above a leaf node or a set of leaves. "This encourages new growth from that point."
FAQs
What tools should you use to prune rosemary?
High-quality tools make pruning rosemary a breeze. We love the look of these Niwaki mini shears from Crocus for larger shrubs. A pair of secateurs are perfect for smaller plants and can be used for deadheading plants, too.
Craig says, "Just make sure to avoid using anything blunt that might cause damage to the plant. Also, don’t forget to clean your tools before and after pruning to prevent any contamination."
Before you start, you may also want to pop on a pair of gardening gloves, such as these ones from Sarah Raven, and invest in a tub, such as this 42-litre one from Crocus, to collect the clippings up neatly.
What are some common mistakes to avoid when pruning rosemary?
Be careful not to prune too much of your rosemary at once, as Craig warns this can impact the chance of it growing back. "It’s best to stick to only trimming about a third of the way down to avoid stunted growth." Keep this gardening tip in mind when pruning lavender in springtime, too.
The team at Wilkinson Sword Tools also advise against pruning during extreme temperatures (either too hot or too cold). Some other garden jobs should also be avoided during these conditions: cutting grass in the heat can be problematic, for instance.
My rosemary is very leggy – can I prune it back hard?
Cutting rosemary back hard can be risky, so it's generally recommended to replace very leggy and woody shrubs instead. For a low-cost option, consider propagating new plants from cuttings. For a quicker solution, rosemary plants are available from Crocus.
Herbs are the perfect way to increase the sensory appeal of a garden, but to give your interior a boost, why not learn how to grow herbs indoors, too? Our guide is full of simple tips to help you try it.
