A Guide to Pruning and Trimming Hedges

A well-maintained hedge makes an attractive and interesting garden feature that will enhance your property and add to its value. Whether you choose a formal or informal hedging species, a certain amount of trimming and pruning will be required to keep your hedge from becoming overgrown and less effective.

To ensure that your garden reaches its full potential, you need to know the ins and outs of hedge trimming, pruning and shaping. Keep reading this helpful guide to discover how to trim hedges, the best time to trim hedges, and specific information on the most popular hedge species in the UK.

Trimming Hedges vs. Pruning Hedges

First of all, you need to know the difference between trimming and pruning. Those who aren’t so familiar with gardening often use these terms interchangeably, but there are actually some key differences.


Maintenance trimming is all about cutting back overgrown hedges to improve and maintain their shape. Trimming is mostly performed for aesthetic reasons, particularly if you want to cultivate a formal hedge. However, hedge trimming can also be beneficial for the plant’s health, as the removal of excess growth can allow more sunlight and moisture to penetrate the foliage to aid growth.

Maintenance trimming is usually performed once a year for informal hedges and twice a year for formal hedges, although some formal hedges can be trimmed three times a year. Overall, the frequency of trimming will depend on the hedge species (maybe its a Photinia Red Robin Hedging Plant) and your personal preferences.


Pruning involves the removal of dead, diseased or pest-ridden branches to improve the overall health of the hedge. In addition, pruning can stimulate the growth of new branches, and if you have a flowering hedge, cutting back dead branches can encourage more fruits and flowers to grow.

In the first couple of years after you plant a new hedge, formative pruning is essential for establishing a dense branching structure. This is because the pruning of top growth in these early years encourages the growth of lateral branches, which leads to bushiness. Once a good branch structure has been established, the hedge can be allowed to grow to the desired height. Annually trimming at least a third of each subsequent year’s growth will maintain density.

When to Cut Hedges

Maintenance trimming is usually carried out between spring and summer, which is the hedge’s growing season. However, the recommended trimming periods can vary between different plant species (more on this later).

Formative pruning should take place immediately after planting, which should be in late winter or early spring. This process will then continue over the next couple of years. After this, the recommended pruning times will vary, but generally, most hedges will tolerate pruning in the winter when they are dormant or during spring.

Nesting Season

Before you start cutting a hedge, you must check for any nesting birds within it. Nesting season runs from March to August each year, so it’s likely that there could be a nest within your hedge during this period.

According to the Wildlife & Countryside Act 1981, it’s an offence to damage or destroy the nest of a wild bird while it’s in use or being built. Therefore, if you discover a nest in your hedge before trimming or pruning, you need to leave it alone and wait until late August before attempting to cut anything back.

How to Trim a Hedge: Formal Hedges

When trimming a formal hedge, you want to ensure that you get clean, uniform edges and dense foliage. For this purpose, electric hedge trimmers are usually the best and most efficient tools, but you can also use secateurs for more detailed work and finishing touches. For advice on how to sharpen secateurs please have a look at this website.

To get the most uniform lines, your hedge trimmer must be clean and sharp. Working with sharp tools can obviously be hazardous, so take precautions such as wearing protective gloves and goggles. It’s also best to avoid using the electric trimmer in wet conditions.

Hedge Shaping

When cutting tall hedges, it’s important to use a ladder to reach the top of the shrub as this ensures greater control and precision. Additionally, you should aim to cut the top of the hedge slightly narrower than the base, creating a tapered shape. This will allow enough sunlight to reach the lower branches of the hedge, thus preventing bare patches due to a lack of sunlight.

Hedge shaping is much easier if you use guides and templates. When cutting a straight line at the top, you should use a guide such as a piece of wood or string suspended between two poles to help you get a clean and straight edge (you may cut through the string with the hedge trimmers). If you’d prefer to cut a different shape, such as an arch, it’s best to use wooden templates as guidance. Hedges with a rounded or pointed top are less susceptible to snow damage than those with a straight, flat top, so you should bear this in mind if you live in a colder climate.

How to Trim a Hedge: Informal Hedges

Trimming an informal hedge is much easier because you don’t have to worry too much about precision. Also, you generally only need to perform maintenance trimming once a year, or whenever your hedge becomes too overgrown. If your hedge ever starts to obstruct a public path, this is when you’ll definitely need to do some maintenance trimming.

Using an electric hedge trimmer is the most convenient way to quickly trim your informal hedges. However, if your hedge has larger leaves, a hedge trimmer could shred the leaves and create an unsightly mess. In this case, it’s better to use secateurs to selectively trim the branches and preserve the leaves.

How to Trim a Hedge: Flowering Hedges

You need to prune your hedges if they produce flowers or berries because cutting away dead, straggly growth can keep the hedge healthy and stimulate flowering. However, pruning hedges at the wrong time of year could mean that you remove the growth that is supposed to flower the following year.

When to prune hedges that produce flowers or berries depends on the type of hedge. For hedges that flower on the current season’s growth, you should prune in spring to allow the plant to flower later in the year. For hedges that flower on one-year-old growth, prune the current season’s growth by half in the summer to get more flowers the following year.

Hedge Maintenance for Upright Plants

Generally, to prevent overgrown hedges, an informal hedge needs to be trimmed once a year and a formal hedge needs to be trimmed at least twice a year. However, the exact guidance for each hedge species will vary.

Hedges can be divided into three categories: upright plants, stocky deciduous plants, and conifers and evergreens. Upright plants, including the Privet hedge, Hawthorn hedge and Box hedge, require a lot of formative pruning after they are first planted in winter, as you need to immediately cut the plant back by a third and then trim the side branches lightly in the first summer. Then, you’ll need to cut the growth back by half in the following winter and trim the side branches again in summer. Finally, in the second autumn, you can cut the leading shoots to the desired hedge height.

For general maintenance, here are some tips for two of the most popular varieties of upright plants in the UK:

When to Trim a Privet Hedge

Green Privet is a fast-growing, semi-evergreen hedge with dense, uniform foliage. Privet hedges make excellent garden boundaries and they should be trimmed twice a year between early spring and late summer to maintain their shape.