Pruning conifers: Why and when is the best time?

Conifer trees are often the preferred choice for people who want to add some nice looking greenery to their yards. What makes them so desirable are several factors they are mostly evergreen, grow rapidly, thrive on negligence and can live in various conditions. They simply require some trimming from time to time, but generally, they tend to keep their form for a long time.

Pruning conifers can depend on the type of tree. In the UK, we have several types of these trees including pine, Douglas fir, Leyland cypress, yew and more. Whichever type you have on your land, it should be trimmed if you want it to look neat. 

Conifer trees are mostly evergreen and are well known for growing rapidly to soaring heights, sometimes up to 100 metres, although there are a number of dwarf, or rather, slow-growing varieties.

The two main questions you probably have are “When to prune conifers?” and “How to prune conifers?” Keep reading and you’ll find all the information you need about pruning conifers.

Why prune conifer trees?

Trimming conifers is always done for a reason. These plants, both shrubs and trees, aren’t used for landscaping and recreational purposes. Shaping conifer trees is needed for the following purposes:

As with any other type of tree, if branches get out of hand and aren’t cut regularly, you risk having them break off in a storm and cause a number of problems. Cutting back conifers’ dominant branches helps prevent bigger and worse issues. What is more, with these types of trees, often there are one or two branches which become dominant and thus suppress the others’ growth. This is also an example of when and why you should trim a conifer tree.

Shaping conifer trees is also done because after some time of negligence they start to look like a nondescript and unshaped shrub. This simply makes you and your home look unsightly, so when you notice that things are getting out of hand, call someone to prune the tree.

If the conifers were planted with a landscaping plan in mind, size control is rarely the reason they are trimmed. However, there are many cases where you don’t have a say in the trees and shrubbery growing around your home so reducing the height of conifers is necessary. 

Due to their rapid growth, they may start blocking sunlight to windows or other plants. Pruning conifer trees is often done by professional tree surgeons, especially if the tree is very high and specialised equipment is needed.

The last but not least reason for trimming conifers is their health. What we mean is that it’s time to trim the tree when there are diseased or damaged branches which can fall off at any time. Also, branches that cross each other or can grow to rub against each other should be cut off because they can become an entry point for disease.

When to prune conifer trees 

Conifer is a broad name for many types of plants including shrubs and trees. All have different types of needles, different growth speed and patterns and thrive with different care and maintenance. There are worst and best times to trim conifers, so be careful not to make a mistake.

When to prune conifers depends on the growth pattern of the type of tree or shrub that you have. We have prepared a list of the most common types of conifer trees in the UK so you can distinguish them easily and have divided them into two categories based on the seasons they should be pruned. 

An important note: Do not trim confers after August because they may get bald patches. Also do not trim them during too hot or too dry weather because the needles may turn brown. These rules are valid for all types of confers.

Types of conifer trees in the UK that need pruning in late spring or early summer when pushing new growth.

Late spring and early summer is the best time to trim these conifers: 

  • Pines - Pines have bear needles, often­times long, and in groups of two, three or five.
  • Arborvitae - This type has soft needles that form sprays along the stems. 
  • Junipers - The foliage of Junipers is borne on its branches in sprays. 
  • Chamaecyparis - This type’s foliage is similar to that of Junipers but it has silver X markings on its undersides. 

But how much to cut down a conifer tree?

Types of conifer trees that need pruning in late winter or late summer when dormant

  • Douglas firs -  The needles are arranged in a spiral around the tree’s stem. Crushing the needles emits a sweet smell.
  • Firs - Firs have stiff needles up and down the branch.
  • Spruces - The Spruces’ needles are extremely sharp and are borne all around the stem. 
  • Hemlocks - This type of tree has short, flat, dark green needles which are slightly stiff. The needles have two white bands on their undersides.
  • Yews - Yews also have short but soft needles which are flat and have a tapered tip.

How to prune conifers?

Pruning method for Pine - This type is to be trimmed during its active growing season. That will give it time to grow new buds for next year. You can use hand prunes or simply break off the branches at the desired length.

Pruning method for Arborvitae, Juniper and Chamaecyparis - These three types of conifers should be pruned on new growth only because they do not grow on old wood. Where you see pliable green stems, that’s where you can safely trim. If you remove brown and old stems, new ones won’t grow back. The reason to trim these trees is for size control. 

Pruning method for Fir, Douglas fir and Spruce - These types are usually cut to control their height. You should prune them during their dormant state. Make a cut half an inch above the buds and it will become the new leader when the growing season begins. 

Pruning method for Hemlock and Yew - The best time to trim these conifers is either in late summer or late winter. After pruning, they get a growth spurt, so it shouldn’t be done when they are actively growing. Furthermore, lightly trimming these types of trees will encourage their fullness.

How much to cut down a conifer tree

For smaller branches and shrubs, you can use your hands or a hand prune. What you must do is gently and lightly cut off the outermost branch tips and deceased or old branches, if any. This is done during dormancy so they can grow and become more full when the tree pushes new growth in spring.

It’s important to remember that the species of the tree matters for the best pruning time. And also to be careful not to overdo the pruning because the tree will end up with bare patches and even the leaves may turn brown prematurely, or worse, the tree may even die. That’s why we would recommend turning to a professional gardener for cutting conifers. They can tell you if the time is right, how much pruning is necessary and can do the job for you much faster and safer than you would. 

Furthermore, if your plant is too high, you definitely would need someone with professional equipment to do the conifer pruning.