Thuja Hedge – Planting, Spacing, Care And Pruning

Last updated on October 23rd, 2023 at 08:34 pm

Thuja hedge, of course, will serve to border the garden, which already somewhat narrowed the choice of location. In addition, however, “the tree of life” needs sun or just light shade to thrive and stay green. If the plants stand too dark, the thuja hedge will instead appear yellowish-brown and pitted.


As a substrate base is enough simple garden soil, which retains moisture well. It should not be too sandy. It is advantageous to optionally add peat dust, humus or some rotted compost to the substrate. This mixture provides the necessary nutrients and also ensures faster and stronger growth of the roots.

Tips for planting the thuja hedge

Thuja Hedge - Planting, Spacing, Care And Pruning

In addition to a sufficiently high nutrient content, the roots of “the tree of life” also need air, so it is recommended to dig up the soil. For planting, holes should be dug that are at least twice as large in circumference and depth as the root ball. Line each planting hole with peat dust, compost or humus.

The thuja plant is inserted so that the root sits about five centimeters below the soil surface. First, it is covered with a thin layer of substrate and finally delineated with another five centimeters of bark mulch upwards.

Immediately after planting the thuja hedge should be abundantly watered. This abundant watering should be continued for the next three weeks, even if it rains.

The optimal time for planting is in late spring or early summer, after the last frost. However, it is also possible to plant the hedge later. Early autumn, before the onset of frost, is suitable. Even then, the plants usually have enough time to grow and prepare for the winter.


Of course, to quickly obtain a dense thuja hedge, it is tempting to plant the individual plants very close to each other. However, this will quickly prove to be a mistake. If the trees of life stand too close together, they will receive too few nutrients and will not be able to spread freely. Within a few months, they would start competing with each other.

It is therefore better to keep a distance of about 40 centimeters. As a result, the hedge will initially have gaps, but these will close very quickly with proper care.


Care of the thuja hedge is uncomplicated, but requires regularity.
It includes watering, targeted fertilizing and pruning if desired.

Thuja Hedge - Planting, Spacing, Care And Pruning


As mentioned above, the thuja hedge is dependent on abundant and frequent watering, especially in the first period after planting. Therefore, it is also not enough to rely on the rain.

Once they have grown, the plants will take care of themselves with sufficient rain. However, in dry and very hot periods, they need additional watering.
However, those who have applied a thick layer of bark mulch when planting will not have to reach for the watering can too often. This is because the mulch stores moisture on the one hand and reduces evaporation on the other. In addition, the layer prevents weeds from spreading along the tree slice and competing with the live trees.


Annual fertilization accelerates growth, strengthens the plants and is an ideal preparation for winter.

Optimally, fertilization is done in mid-summer and is followed by a large watering. Suitable agents are commercial hedge fertilizers, rich in magnesium and nitrogen. If fertilization was forgotten in the summer, it should not be made up in the fall. If the nutrients are applied too late, the thuja hedge will not be able to prepare for the dormant period in winter.


Basically, the thuja hedge – except for frosts – can be pruned all year round. However, it is really convenient to carry out this measure only at two times.

In spring, before the first shoots appear, and in late summer. In each case, it should be done very gently and carefully. The following tips will help to pay attention to the most important points.

  • When pruning the thuja hedge, shorten only young shoots.
  • Remove only a few centimeters at a time
  • Keep the hedge wide at the bottom and taper it towards the top
  • Pay attention to even shortening
  • If possible, use a taut thread as a guide

Restrained shortening is particularly important for the thuja hedge, since holes once created – as they will inevitably occur when cutting too radically – can only be closed with difficulty or not at all. For this reason, care should also be taken when removing brown branches. It is therefore clearly better to prune only a little twice a year than to remove a lot once.

The upward tapering shape is crucial for three reasons at once. If the tips are narrower, they allow more sunlight and water to reach the lower areas. This reduces the risk of brown discoloration. At the same time, this prevents snow from accumulating on the tops, which in turn reduces the risk of breakage of the thuja hedge

Tip: The thuja hedge is not only beautiful to look at, it is also popular as a nesting site for birds. Therefore, depending on the state, larger cuts may only be made at certain times. Even outside the legally stipulated times, however, every hobby gardener should first take a close look and look into the hedge. If occupied nests are found, pruning should be refrained from}Protection of the interfaces

The thuja hedge is hardy and robust in itself, but its fresh cuttings are not. If exposed to the sun, they can burn within a very short time, leaving the plants with an unsightly brown surface.
Therefore, not only is the right time of year crucial, but so is the current weather. It is best to choose an overcast day and water the hedge well immediately afterwards.

If you can not wait until optimal lighting conditions, you can help yourself with a little trick. To do this, in the first place it is necessary to cut quickly. Electric or gasoline hedge trimmer is suitable for this purpose. Once an area is formed, it should be covered with garden fleece. This provides shade and prevents evaporation at the interfaces. This gives the thuja hedge an opportunity to close the cuts.

In the case of prolonged strong sunlight, the fleece can quietly remain on the hedge for up to two days. However, longer covering is not recommended, because heat can accumulate under the fleece. Normally, it can be removed by nightfall on the day of cutting.

By the way: Other materials, such as foil, are not suitable as protective covers. Because under them, if necessary, the heat and radiation will be amplified.

Care of the tree

Thuja Hedge - Planting, Spacing, Care And Pruning

Especially shortly after planting, but even after several years of standing, weeds can become dangerous competition for the trees of life. Therefore, special attention should be paid to them. If they are found in the immediate vicinity of the hedge, they must be removed immediately.

If you want to waste as little time and energy on this as possible, again rely on bark mulch. A thick layer of this usually prevents the spread very effectively and also facilitates removal.

Protection in winter

Thuja hedges are hardy and therefore do not require further protection in the cold season. However, it may happen that the hedge turns brownish or entirely brown when the days become shorter. If this happens reasonably evenly, the color change is not a cause for concern. Instead, this is a natural form of adaptation.

How severe the discoloration is depends on the variety chosen.
If you want to have a green Thuja hedge in the garden even in winter, you should choose the cultivated form Smaragd.{infobox type=check|content=Tip: In dry winters, it may be necessary to water the Thuja additionally to prevent it from drying out. However, watering should only be done on frost-free days}.

Typical diseases and pests

Basically, the tree of life is a robust plant that, with proper care, does not fall victim to diseases or pests.

Although infestations can occur even in healthy trees of life, they keep themselves within limits. If a pest infestation or severe disease does occur, you should always take a look at the location, watering habits and soil quality. Once the fault has been found, this will prevent further diseases and damage. Typical pests and diseases of a Thuja hedge are:

  • Thuja bark beetle
  • Thuja leaf miner caterpillars
  • Fungi, such as Didymascella and Kabatina thujae

Infestation with the above-mentioned insects is manifested by dying branches and shoot tips, which initially turn brown and show signs of feeding or thickening. However, those who carry out regular pruning need not fear them. After all, even removing the shoots deprives the pests of their nutritional basis.

The aforementioned fungi show themselves in spot or dot-like discolorations, which can be brownish or even black. Around May, the spore deposits break open, thus spreading the fungus not only on the thuja hedge, but throughout the surrounding area. Therefore, timely pruning is also a crucial countermeasure here.

If the removal of affected parts does not help, appropriate means from the trade can be used.

In the long term, however, an effective countermeasure is only optimal care. Because healthy, strong trees of life, which have sufficient water and nutrients and are also regularly pruned, are significantly less likely to be attacked by pests or diseases.{infobox type=check|content=Tip: Do not dispose of the pruning residues in your own garden, but rather well packaged via the household or organic waste. Appropriate recycling centers are also suitable places to go. This is because both insects and fungi will continue to spread from the remains}.

Is the thuja hedge poisonous?

As beautiful as the tree of life is, it is not harmless. Even light contact with cuts or fractures and the sap that escapes from them can irritate the skin, cause vomiting, diarrhea or organ damage.

The effects are even more significant if parts of the plant are consumed. If children and animals play in the garden, the choice should therefore rather fall on non-hazardous hedge plants.

Tip: To protect against the irritating sap of the thuja, wear waterproof gloves when cutting and wash clothes thoroughly immediately afterwards.


The thuja hedge is a fairly fast-growing and dense privacy screen that requires only simple care and is therefore well suited for novice gardeners. Under optimal conditions, it is not very susceptible and quickly develops into an imposing border. However, due to its toxicity, some caution is needed in handling.


  • James Jones

    Meet James Jones, a passionate gardening writer whose words bloom with the wisdom of an experienced horticulturist. With a deep-rooted love for all things green, James has dedicated his life to sharing the art and science of gardening with the world. James's words have found their way into countless publications, and his gardening insights have inspired a new generation of green thumbs. His commitment to sustainability and environmental stewardship shines through in every article he crafts.

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