Pruning conifers: when and how do you do it?

Almost every garden has a conifer—either as a standalone tree or as a conifer hedge. They offer many advantages: they grow quickly, provide privacy, and most varieties are evergreen year-round. But to keep them under control, you need to prune your conifers regularly. When and how is the best time to prune, and how often should you prune?

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Good to know: a 'conifer' isn't just one specific tree, but a group of over 600 species. The name literally means 'cone bearer' (conus = cone). Well-known conifers in the garden include yew and scale conifers like cypress and arborvitae ( Thuja ). But not all conifer species need pruning. Think of coniferous conifers like pines and spruces. So always check carefully which type of conifer you have before you prune.

Tip! Not sure which conifer is in your garden? These plant apps might be able to help!

Conifers grow quickly and can quickly become too tall or too wide. This can cast a significant shadow in your garden or your neighbor's – potentially leading to a dispute. To control their size, you should prune your conifers regularly. This removes dead and diseased branches, improves air circulation, and results in a fuller, more attractive hedge or tree.

Conifers are usually pruned several times a year. Depending on the type of conifer and the specific work to be done, pruning occurs at different times, but generally speaking, conifers are trimmed between April and the end of August. Fast-growing conifers (such as the Leyland cypress) require three to four pruning sessions per year, while a yew generally only needs to be pruned once a year.

Many trees are pruned in winter, but pruning conifers in February isn't a good idea because they won't be in top form then. It's better to wait until late spring, after the Ice Saints . Then the plant is strong and many young, green shoots will appear. Complete this spring pruning before the longest day of the year, June 21st. It's best not to prune in midsummer, as scorching can cause unsightly brown spots on your conifers.

Conifers should be pruned from late summer to early autumn, in August or September at the latest. Trimming your conifers during this period gives them time to recover properly from pruning before winter, ensuring your conifer hedge stays neat and tidy all winter long.

Pruning a conifer hedge is actually quite simple. The biggest challenge is to trim the hedge neatly and straight.

Hedge trimmer or hand shears

Before you begin, always check that no birds are nesting in your conifer. Otherwise, you'll have to postpone pruning. Also, always make sure any ladders are secure and that you have sufficient support before you start. Safety always comes first!

Place a cloth on the ground to catch all the cuttings. To trim the top evenly, insert two long bamboo poles into the hedge. Stretch a string taut between them and check that it's level. This will serve as your guideline.

Trim the top of the hedge by holding the hedge trimmer horizontally with both hands and using the string as a guide. Wear safety glasses and gloves, and for tall hedges, make sure you have a secure footing on a ladder or scaffolding.

Tip!

Trim the sides of the hedge using the string as a guide. Hold the electric hedge trimmer vertically and use long, sweeping strokes for an even result. With manual shears, always trim from bottom to top.

Remove the stakes and string and assess your work. Use the hedge trimmer to further trim the top edges where necessary, and then clear away any pruning debris.

Pruning neglected conifers can be quite a challenge. Start by removing dead or diseased branches. Then prune gradually over several years, removing no more than about one-tenth of the living greenery each year. Begin by pruning the tops and sides to achieve the desired height and width.

Many conifer species don't re-sprout if you prune into old wood, so don't cut them back too far! The yew is an exception: it can re-sprout from old wood. It can take several years for a neglected conifer hedge to fully recover, so be patient! If the hedge has become extremely overgrown, consider calling in a professional or replacing it – for example, by taking cuttings .

If your conifer hedge is too wide, first determine its desired width. Then, use rope and stakes to mark the new width on both sides. Work gradually: prune in stages over several growing seasons. Each year, remove no more than a third of the excess width. This prevents your conifers from turning brown or developing bare patches.

Do you have conifers in your garden? Then consider topiary ! Conifers with finer needles that grow close together, such as yew and giant red cedar ( Thuja plicata ), are particularly suitable. You can add an extra design element to your garden, or you can use conifer hedges to define garden rooms*.

* A garden room is a defined area of a garden, often with a specific theme that connects the plants in that room. Such a room can also have its own purpose. By creating several garden rooms, you can essentially create several smaller gardens within a single garden.