Trimming back your hedges can make a huge difference to the overall appearance of your outdoor space.
Whether you’re giving your plants a freshen-up after the long winter months or you’re looking to tame your hedges for the first time, our beginner’s guide on how to trim a hedge will help you to keep them looking at their best.
We’ll walk you through the tools you need to get the job done and when the best time to cut your hedge is, as well as some top tips for encouraging neat and healthy hedges.
What are the benefits of trimming hedges?
There are two main types of hedge trimming: maintenance trimming and formative pruning. Each has its differences and benefits.
- Maintenance trimming – This aims to neaten up a plant’s branches and leaves, as maintenance trimming is primarily for aesthetic reasons. Cutting back any overgrown areas helps to give it a more defined shape. It can also be performed when a plant is encroaching onto its neighbours and needs to be trimmed back.
- Formative pruning – Formative pruning is quite the opposite of maintenance trimming, as it’s done to promote hedge growth rather than restrict it. It removes any dead, dying, or diseased leaves and branches to prevent them from spreading to nearby plants. It may also encourage a hedge to bloom flowers or fruit. This technique is also useful for encouraging the shape of a hedge.
When is the best time to trim a hedge?
Newly planted or young hedges will need formative pruning once a year, up to around five years after planting. The best time for formative pruning is wintertime or early spring. This is because all the leaves will fall off the structure, making it easier to see what you’re doing and identify which areas may need your attention.
Maintenance trimming can be done once a year to keep most hedges tidy, however, some faster-growing species may benefit from two or three cuts a year. Summer is the best time for maintenance trimming, as this is when hedges are in their most active growth period.
However, not all species grow at the same rate and some have different needs. For a more detailed breakdown of when the best time to cut a specific hedge species is, take a look at our quick guide to timings below:
What tools do you need to trim a hedge?
The tools you need depend on the size of your hedge:
For a small hedge with thinner branches, a pair of hand-held shears will get the job done. These are essentially a large pair of scissors for trimming back overgrown branches.
While trimming a hedge with shears will require more effort than with an electric tool, manual shears give you more control. They’re an excellent option for achieving precise shapes or for a beginner who may struggle with an electric trimmer.
Shears with telescopic handles can be extended to help you reach higher.
Secateurs – smaller gardening scissors that can be used with one hand – are also available for intricate cuts and fine-tuning jobs. This versatile tool is great for trimming individual leaves and stems as well as thicker branches.
For larger structures or gardens with lots of hedges that need attention, a pair of hedge trimmers is a handy tool to have in your arsenal. The moving blades are usually powered by electricity or petrol to make pruning a quick and effortless job.
Hedge trimmers require lots of practice and careful use, so they may be more suitable for experienced gardeners. It’s important to always take the correct safety precautions before and after trimming, whether you’ve used hedge trimmers before or not.
Safety gloves and goggles are essential and trimmers should never be used when it’s raining or the ground is damp.
How often should you trim hedges?
When it comes to trimming your hedges, formal or informal hedging will also inform when and how often it should be cut.
Hedges with a well-defined structure are formal and they tend to be used to add character and style to outdoor areas. Formal hedges are characterised by a very neat and compact shape with tightly clipped edges. Since they have a tidy appearance, they require more regular clipping to maintain their polished look.
Generally, formal hedges are best trimmed into a tapered shape where the base is bigger than the top half of the structure. This is called cutting the hedge to a batter and it enables light to penetrate through to the lower branches of a hedge and gives it a fuller appearance.
Informal hedges tend to have a more natural shape and looser structure. The best informal hedges have large leaves and colourful blooms or berries. Once established, they can largely be left to their own devices and only need to be trimmed once a year.
Informal hedges are best cut after they have flowered as it can help to encourage flowering the year after. If your informal hedges are at the boundaries of your garden, you may want to prune them less often so they can grow more to give your garden added privacy.
How to trim hedges
There are three different categories of hedges when it comes to trimming: upright plants, deciduous hedges, and conifers and evergreens.
Here’s how to tackle them.
The best time to trim hawthorn hedges is in the summer during the growing season. A cut in May will put the shape back into the structure, which may need a top-up around September time when the leaves and branches start to grow out.
Remember to trim the top so that it’s level and to keep the bottom half of the hedge wider at the base.
Privet hedges can be trimmed as early as spring. Keep an eye on its growth and aim to cut back six to eight inches from the ground whenever you notice a foot of growth. This will help to promote branching at the base and even root growth.
Make sure to stop any trimming activity in late summer as you want to slow the growth through autumn and winter.
Buxus hedges require trimming twice a year: once in June and then again in early autumn. Try to pick a day when conditions are cloudy so as to avoid the sun burning any young, soft leaves.
Spring is also a good time to cut away any dead or diseased branches.
Beech hedges are naturally bushy, so formative pruning is best done in June and August to encourage the plant to sprout new leaves and grow out any bare spots over winter.
Similarly to beech, hornbeam hedges often have a compact plume of leaves which can benefit from formative pruning twice a year: first in June and later in September to encourage growth to last through the winter.
The best time to trim hazel hedges is between February and April. The optimal time depends on the hedge in question: cut leaves and branches back after the catkins have dropped but before any new leaves start to form on the stems.
Hazel hedges don’t respond well to severe pruning, so try to only cut diseased or broken stems.
Conifers and evergreens
Cherry laurel is best trimmed in the summer months, July or August, to promote growth. Try not to prune past summer as cutting it back any later can make it vulnerable to winter damage.
Cherry laurel leaves are notoriously tough to prune, so secateurs will be the best tool for the job.
Yew hedges are one of the most forgiving plants to prune and can tolerate being trimmed back any time of year except for winter. The best time, though, is in summer to help keep the structure neat and tidy.
Yew is extremely poisonous, so we strongly recommend wearing gloves when pruning and removing any cuttings,
Leyland cypress can be trimmed multiple times throughout the year, starting as early as April through to August. Avoid cutting it back any later than August though, as Leyland cypress will require the rest of the year to recover for the colder winter months.
Despite its quick-growing nature, try not to cut it beyond its top-level of green leaves. Trimming past this can cause irreparable damage to the hedge.
Top tips for trimming hedges
1. Always keep your tools sharp and clean
Regardless of whether you choose to use shears or electric trimmers, keeping your tools well-oiled and the blade sharp is important for effective hedge trimming.
Always give your tools a clean after each use to reduce the chance of spreading disease and cross-contamination. This will also wash away any sap which can accumulate and solidify on your tools.
2. Check any trees or hedges for birds’ nests before trimming
Before you pick up any tools, you must check for any nesting birds or birds’ nests in any hedge or tree that you’re planning to trim.
Under Section 1 of the Wildlife and Countryside Act (1981), it’s an offence to damage or destroy a wild bird’s nest. To make sure you’re not breaking the law, look out for any potential signs of nests before deciding to trim.
If you spot any activity in your plants, you must wait until after autumn when the chicks have left their nest before trimming. August to March is often the best time to trim your hedges as birds don’t tend to nest in the winter.
3. Dispose of clippings straightaway
Once you’ve trimmed your hedge, always dispose of clippings immediately. If you don’t, dampness can promote fungal diseases which risk spreading to other greenery in your garden.
To help make the clean-up easier, lay down a tarpaulin sheet on the ground around your hedge. This will catch any clippings that fall. After trimming, use a rake on the top of your hedge to knock off any stray clippings. Gather these up into the tarp and dispose of them in your compost.
4. Use a template or guide for the best results
Trimming a hedge free-hand without any reference can make it difficult to achieve precise results. Bamboo canes attached together with a length of string are actually a really useful device for getting a neat and straight edge. Run this along the top or sides of your hedge to use as a guide to cut along.
For more elaborate shapes, like arches or domes, some gardeners find it useful to create a wooden or cardboard template to cut around.
Once you have the right tools and the best conditions for the job, trimming a hedge isn’t as difficult as it may seem. For more expert gardening tips, take a look at our blog.