Thuja – how to succeed with planting and pruning

Thuja 'Brabant' is the most common thuja variety, with light green shoots that darken over the years. It grows quickly and is easy to shape. Thuja 'Smaragd' is another sure winner; it grows a bit slower than 'Brabant' but has a deeper green color and a denser growth. Both are evergreen and stay beautiful year-round.

• Growing conditions
  Thuja thrives best in full sun to partial shade. It can also do well in more shaded areas.

• Soil conditions
  Thuja prefers nutrient-rich, well-drained soil. It does not like to have its "feet" in water, but it does prefer a consistently moist soil that is slightly acidic.

• Watering needs
  Thuja prefers consistently moist soil. If the soil becomes too dry and poor, the plants may produce a lot of cones. Water as needed. When watering, it's important to water thoroughly to ensure that the water reaches all the way down to the roots. It’s better to water deeply and infrequently rather than often and lightly.

• Nutrient needs
  Fertilize in spring, around Midsummer, and no later than the end of July or early August. Remember that it is quickly soluble, so avoid using too much to prevent burning the roots.

• Pruning
  Only trim the sides until the hedge reaches the desired height. Afterward, it should be pruned annually in both height and width. A thuja hedge will look its best when regularly pruned. The best times for pruning are in spring after the frost has left the ground and just before the growth starts, as well as during the months of July, August, and September.

When planting thuja, there are a few simple but important things to consider first. Here, we show exactly how to proceed and what to think about when planting thuja as a solitary plant or hedge.

If you buy a thuja that has been grown in a pot, it will establish itself and start growing quickly once planted, as the root system is already in place. This can be planted in the fall. Thuja in sacks/netting is best planted in the spring, as it needs more time to properly root. When planting, you should mix the existing soil with planting soil.

• If you are planting several thuja trees in a row, a good rule of thumb is to place three plants per meter. However, if you choose a larger variety of thuja, they should have more space between them, and if you use smaller thuja trees, they can be planted closer together.

• When planting a hedge, it's best to dig a trench about 50 x 50 cm. This way, all the plants in the hedge will have the same growing conditions, and the result will be more uniform.

• Water well and add soil around the plants, then press down firmly so that the plant is stable in the hole. Water again afterwards. Note! If you buy a rootball plant (with netting around the roots), do not remove the netting.

The thuja needs to be watered properly until autumn to ensure it has enough water through the winter. When the winter and spring sun starts appearing again from January onwards, it may be wise to cover the thuja with burlap or a shade curtain to prevent the sun from drying out the foliage while the frost in the ground prevents the thuja from absorbing water. Once it gets warmer and the frost has melted, you can remove the protection.

A thuja hedge can grow quite tall. Do not trim the top of the thuja until it has reached the desired height. While the hedge is growing to the desired height, you can instead prune the sides by simply trimming off any branches that stick out. A good rule of thumb is to try to keep the hedge even and just as dense all around. Thujas can be pruned both in spring and autumn.

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