Thuja pruning according to the rules: how to avoid seven common mistakes

Thujas are evergreen trees with attractive, scaly leaves arranged in short branches. Like most conifers, thuja does not produce new shoots on old, bare stems, so they do not tolerate rejuvenation or very severe pruning.

So what mistakes should be avoided while pruning thuja trees?

When to prune thuja?

The ideal time to prune thuja is late spring or early summer, before new shoots appear, but sanitary pruning can be done at any time.

Before pruning, the growth characteristics and variety of a particular species should also be taken into account – the specific time of pruning depends on how much the tree needs to be trimmed. To maintain a decorative appearance, remove excess shoots in spring and adjust the shape in mid-summer.

If you want to control thuja growth, it is enough to cut them hard at the end of August. At this time of the year, the juice is drained downwards, so the growth of the thuja slows down a bit.

If the trees are cut in the spring, a lot of sap is released and the growth of thuja accelerates, so this is an ideal choice if you want to grow a hedge from thuja and hide it from the prying eyes of neighbors as soon as possible.

If the thuja needs to be pruned more, do it before the end of the dormant period, when active growth begins in early spring. In the spring, as soon as the weather warms up, the cuts are covered by new shoots, so they are less noticeable.

To trim the hedge, wait until late spring or early summer, after flowering has finished. Try to do this before mid-summer so that the thuja has time to recover before the autumn frosts.

Thuja pruning according to the rules: how to avoid seven common mistakes

How to cut thuja?

If you cut small thuja trees, you do not need any special and expensive tools – basic tools are enough, regardless of the size of the branches. As always, use appropriate personal protective equipment.


  • Manual secateurs for branches less than 1.5 cm in diameter;
  • Garden scissors for cutting branches 1.5-3 cm thick;
  • Pruning saw or reciprocating saw for branches thicker than 3 cm;
  • Protective glasses for eyes.

If you want the tools to cut branches quickly and evenly, don’t forget to update and sharpen them regularly. Leaving the incision open increases the chance of insect or fungal infection.

It is recommended to clean the blades of the tool after each pruning. It does not take much time, but it prevents diseases from spreading among the trees.

How to cut a thuja: general rules

Try not to remove more than 30 percent in one season. shoots. Also, remember to cut only green, young wood. Work in sections to make fewer mistakes. Avoid cutting horizontal branches.

Thujas are conifers with thorns instead of leaves; These fan-shaped shoots grow from buds at the tips of new, green branches. Due to the nature of this growth, branches should not be cut too deeply. If you cut down an old tree, new branches will not grow from it.

If your thuja needs serious pruning, trim the tips and tops of the branches. This ensures that you are only cutting young wood and not old wood.

Regardless of the shape of the hedge you want to maintain, prune thuja annually or every two to three years.

Using pruning tools, remove vertical shoots that obscure lower branches, leaving three leaders on each branch. Remove any branches that point toward the center to ensure sunlight and air circulation within the tree.

Thuja pruning according to the rules: how to avoid seven common mistakes

Removal of old and dead branches

Thujas are quite resistant to pests and diseases, which is why they are so popular. If a dead or diseased shoot appears, it should be cut immediately.

Begin cutting immediately below the dead needles; Continue cutting the branch in a downward motion until you reach the middle of the green shoot. As a last resort, remove the branch completely by cutting at the point where it branches off the trunk. Discard or burn suspect branches away from other trees and plants. Never throw diseased branches into the compost pit.

The method of pruning thuja depends on its type and what shape you want to give or keep. When pruning a thuja, step back every few minutes and assess the shape of the thuja.

  • Ball-type thujas naturally expand through the center. By trimming them regularly, you will maintain their neat appearance. Trim the tips of all the branches so that the shape is uniform. The root or middle of this thuja should be wider than the top.
  • The purpose of pruning tall thuja trees is to maintain the pyramidal shape. The lower part of the plant should be wider than the upper part, so that light and air can pass through the branches.

Three good reasons to prune thuja trees

Thujas generally don’t need much pruning, but there are a few important reasons to pick up a saw or shears.

1. Thuja grew very tall.

It is often possible to reduce the height of the leader. It is wise to reduce it to less than a third. With a slight diagonal cut, shorten the remaining branches by a few centimeters – this will hide the cut and preserve the natural shape of the thuja. The highest surviving branch becomes the new leader.

2. Protruding or bent branches

If it does not leave a big hole in the overall appearance of the bush, remove protruding, low-level, bent and bent branches. In some cases, the branch breaks out of the tree’s neat shape because it simply bends under the weight of so much snow. After pruning a third of the bent branch, it can rise again and blend harmoniously into the overall shape of the tree.

3. Thuja is very spreadable

Cutting such a thuja is difficult, especially if the tree is extremely stunted. However, selective pruning can help in this case. Find long branches, slide them into the crown, then shorten or remove these branches. The remaining short branch tops form the desired, slightly narrow thuja profile. However, cutting overgrown thuja trees with this method is a very tedious task, so sometimes it is easier to cut them down.

7 Common Mistakes Made When Pruning Thuja Trees

  • Old wood is cut. This creates voids that take many seasons to fill. Prune only actively growing branches to allow them to regrow.
  • Extreme pruning. Do not cut more than 25-35%. Thuja
  • You cut the horizontal branches. They are an integral part of the overall shape and structure. Cut them only if they are diseased or dry.
  • Cut too close to the buds. Try to cut about 15 cm from the buds. If you cut too close, the buds may die. If you cut too much, the branch ends may die.
  • Cut the whole tree at once, not in parts. When pruning in parts, fewer mistakes are made and uneven work is avoided.
  • You are working with loose or dirty tools. Gardening tools should be sterilized before and after pruning – this helps prevent the spread of disease.
  • You are cutting the top wrong. Cut the top of thuja only if you want to stop upward growth and form a hedge. Thujas do not grow new leaders like deciduous trees.

It is strictly prohibited to use information published by DELFI on other websites, media or elsewhere or to distribute our content in any form without consent and if consent is obtained, it is necessary to credit DELFI as the source.

Leave a Comment

Your email address will not be published. Required fields are marked *