green hedges in the garden

Best Time to Cut Hedges Back: when and how

Hedges are one of the most common features in many prestigious and established neighborhoods. Because of their versatility – coming in a variety of sizes, shapes, and even species – they can fit beautifully into almost any landscape. But shaggy, overgrown hedges are far from beautiful. Regardless of their sizes, or whether they’re evergreen or deciduous, it’s important to trim your hedges. And to trim them at the right time. In this article, we’ll cover the reasons why you should – or shouldn’t – trim your hedges as well as the best time to cut hedges back.

Why should you trim your hedges?

Frequent trimming is essential for healthy hedges. Periodically trimming and pruning your plants means that they will benefit from increased sunlight, better airflow and improved water delivery to the roots. This can help prevent keeping your plants in optimal condition and reduce the risk of diseases.

Trimming is also an effective way to direct the growth of your hedge. Precisely cutting back branches or foliage can lead to a healthy hedge. While new hedges need pruning to encourage growth, established hedges also require trimming to keep them dense and compact.

Formal hedges will typically require more frequent trimming than informal hedges in order to maintain precise shapes and lines.

What happens when you trim your hedges regularly?

When you trim your hedges regularly and properly, you will begin to notice that the plants fill in nicely and provide more privacy. By trimming away plant growth that is moving outward or upward, you can encourage the plants to fill in around the center.

It is essential that you have a good hedge trimmer, that it is sharp and in good condition. Old blunt hedge trimmers will damage the branches and cause the plant stress to close torn ends rather than clean cut edges.

Trimming your hedge into a wedge shape that is wider at the bottom will make it grow thicker by enabling more even regrowth. Cutting back the top of the hedge will encourage growth at the sides of your bushes.

Trimming out dead or diseased parts of the plant will also keep the hedge healthier and allow for new growth. Removing any dead wood reduces the risk of insect problems in the hedge as well, leaving fewer access points for them to burrow in.

What happens if you don’t trim your hedges regularly?

Unfortunately, many individuals fail to prune their shrubs – they may lack the time, knowledge, or courage to handle their hedge-trimming. But when neglected, shrubs can often become leggy and unattractive and some flowering shrubs may no longer bloom as well.

Without regular pruning, hedges can quickly grow beyond their boundaries, creeping onto neighboring properties or overhanging the street or sidewalk. 

When should you not cut your hedges?

green beautiful hedges

There are several guidelines to keep in mind when planning when to cut back your hedges.

In many areas, it’s actually illegal to disturb wild birds that may be nesting in your hedges. For example, it’s an offense under the UK the Wildlife & Countryside Act to damage or destroy the nest of any wild bird while it is in use or being built. And although the WCA doesn’t specify any dates, the main bird breeding season is typically between March 1st and July 31st.

Check your hedges for wildlife

If you’re planning to undertake any work within these dates, I recommend checking the hedge for any signs of breeding activity before you begin – you could stake out the hedge with a pair of binoculars in hand, or gently search through the bushes for nests. You should stop working immediately if you suspect that any birds are living or nesting in your hedges. The job can always be delayed if necessary.

Some plant species will not respond well to pruning at certain times of year. Others will only thrive if trimmed at set times. Typically:

  • Coniferous hedges shouldn’t be trimmed after August, as this can encourage bare patches to develop in the hedge.
  • Evergreen hedges shouldn’t be clipped when they are dry, so during the summer, you should water the hedge the evening before you trim it.
  • Some flowering shrubs, like camellias, flower from late summer through winter and require spring pruning.
  • Shrubs that flower in the spring or summer should be pruned immediately afterwards regardless of the season.
  • If a plant produces flower buds on old wood soon after it finishes the current season’s bloom, always prune it afterwards.

How far can you trim back hedges?

While some hedge plants can thrive after a hard pruning, others require more delicate handling. In fact, many deciduous shrubs can be kept healthy and vigorous simply by removing a few of their largest, oldest stems every 2-3 years.

If your hedges do become overgrown, leggy, or shaggy, proper pruning can renew or rejuvenate them. You can do this gradually, by pruning them back over a 3-year period:

  • Remove one-third of the large, old stems at ground level in late winter or early spring
  • The following year, prune out half of the remaining old stems and some of the new growth, leaving several well-spaced, vigorous shoots
  • Remove all of the remaining old wood in late winter or early spring of the third year and thin out the new shoots.

Severe pruning

A second, more severe way to prune overgrown, deciduous shrubs is to cut them back to within 4 to 6 inches of the ground in March or early April. This encourages a large number of shoots to develop during the next growing season. In late winter of the following year, you should choose several strong, healthy shoots to retain and then remove all the others at ground level. If you want to encourage branching, you can also back the shoots that you’ve kept.

While overgrown lilacs, honeysuckles, dogwoods, spireas, and forsythias may be pruned in this manner, it’s important to note that your lilacs will be unlikely to bloom for 3-5 years after a hard pruning.

Deciduous, formal hedges that become too sparse or leggy can also be rejuvenated by pruning them back to within 4 to 6 inches of the ground in late winter or early spring. For a full, thick hedge, you can prune the shoots often as they grow back over the spring and summer.

Can you trim a hedge too much?

Overgrown evergreens, such as junipers, can be a problem as they tend to develop bare spots or dead zones in their centers. They can’t handle a hard pruning because they’re unable to develop new growth from bare branches. So, junipers that have become too large or unattractive should instead be removed and replaced with new shrubs.

Remember that your hedge should be fertilized and watered deeply after a severe trimming to give the plant the nutrients and water it needs to support vigorous new growth – particularly as it now has few leaves with which to photosynthesize and produce its own energy. Without this extra help, a hedge may struggle to recover after a hard pruning.

When is the best time to cut your hedges back?

To encourage even growth of your hedge plant, trim it at the right time of year – but every plant species may have a different schedule.

So, when is it best to cut back your hedges? As a general rule, the dormant period over winter is the best time to prune and trim back your hedges, but dead wood and smaller branches can be removed at any time. Late winter and early spring are the best times to cut back an overgrown hedge and summer is best for the smaller, more precise trims meant to shape the hedge and control its height.

Informal hedges can usually be trimmed annually and more formal hedge should be pruned twice every year – some may even need three cuts a year to look their best. Cutting back new growth at the top of the plant in the spring leads to a thicker hedge in the Summer and trimming into late autumn or early winter will encourage root growth.

Or, you could create some topiaries and spend a little time each week grooming and prodding them into fantastical shapes. What do you say?