Trimming hedges, the right time

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When should a hedge be trimmed, what is the right timing, and how should one go about it best?

Often used to mark property boundaries, or simply to fence out special portions of the garden, a hedge usually requires little care: at most, trimming once or twice a year.

Follow our advice to get nice hedges all year round.

• Important: read up on local regulations about trimming hedges

The right time to trim a hedge

Hedges are usually grown from shrubs that have two vegetation phases within a year, one in spring and another at the end of summer.

Best is to wait for these growth periods to slow down, so that the shape you give them will stay for a longer period of time.

• Consequently, from the shrub’s point of view, hedges need trimming in April-May and September-October.

However, in spring, this overlaps with bird nesting periods.

• As a result, you should prune much earlier in spring: early March and even February are ideal since birds aren’t nesting yet.

To control growth more precisely, hedges can be trimmed more often. Topiary is one such example of when trimming has to be very frequent.

As for flowered hedges, wait for the blooming to be over before pruning.

When to cut a hedge back

If you need to drastically reduce the size of your hedge, it’s best to do so very early in spring: end of February or first half of March.

• This will give your shrubs the most chances of bouncing back lush and dense.
• Example: cutting back thuja shrubs by a lot

• Conifers such as thuja and cypress will not resprout from bare brown wood, so keep every cut within the green, needled part of the branch.
• Broadleaved hedges like privet, hornbeam and laurel take renovation far better and will shoot again from old bare stems.
• When renovating an overgrown deciduous hedge or yew, hard-prune just one face in late winter, leaving the opposite side untouched for a year or two until the cut face has re-clothed itself.
• After a hard cut, water and mulch the base so the shrubs have what they need to push out new shoots.

Which trim, and when: a quick guide

Not every cut is made at the same moment of the year. Match the job you have in mind to the window that suits it.

Once the timing is settled, the way you hold the blade decides the rest.

Techniques to trim a hedge

Trimming a hedge well helps maintain it over the years, ensuring sufficient density to remain opaque and optimizing hedge growth.

• The base must be trimmed wider than the tip.
  This helps give light to all the shrubs that are part of the hedge.
• Use an electric or gas-powered hedge trimmer for hedges longer than 16 feet (5 m) long, for better accuracy and especially easier workload.
• Use pruners for the larger branches.
• Shears are more accurate, which helps for lower hedges.

• Stretch a string line between two canes at the finished height and trim to it, so the top of the hedge stays level from end to end.
• Sharpen the blades first: blunt ones bruise shoots and leave brown tips.
• Work each side from the bottom upwards so the clippings fall clear of the hedge, then finish the top.

Shrubs that make for good hedges

There are a great many hedge shrubs, but some are particularly well suited to hedges because they cope well with pruning.

Indeed, strawberry tree, wild privet, weigela, cypress, camellia, photinia, and flowering currant are perfect for hedges.

• Go for green all year-round and start an evergreen hedge.
• Or create a flowered hedge that blooms as seasons fly by.
• Attract birds with berry shrubs.
• Learn to create mixed hedges which are great barriers against diseases and parasites.

Here is a video on how to plant hedges

Read more about pruning:

• Laws about trimming hedges
• Guidance on pruning shrubs
• Ornamentals: pruning boxwood, hydrangea, roses
• Fruit trees: pruning grapevine and other fruit trees