Thujas are hardy garden plants and come in many different species and cultivars. The group of plants, also known as the tree of life, is ideal as a hedge plant, planted out individually in the ground or in large containers on balconies and terraces. A hedge of thujas can serve as noise and privacy protection for decades. With optimal site conditions, Thuja plants grow more or less quickly depending on the species, are robust and tolerate pruning well. A permeable, humus-rich location without waterlogging is essential for the coniferous tree. Learn below how to plant and maintain an opaque Thuja hedge.
Worth knowing Location Planting Watering Fertilizing Pruning In the tub Care & Overwintering Species Pests & Diseases FAQ
Interesting facts about thujas
Botanical name: Thuja occidentalis, Thuja plicata Thuja orientalis
Other names: Occidental arborvitae, giant arborvitae, emerald, Brabant, Oriental arborvitae
Use: hedge, single position, container plant, evergreen shrub
Origin: North America and Asia
Needle color: green, yellow
Special features: the plant genus Thuja is available in many different varieties.
There are species that stay small and grow spherically, while others are trees up to 15 m high. Depending on the variety, the annual growth can be a few centimeters up to 35 cm.
The coniferous tree is very popular as an evergreen wall because of its dense growth. The best time to plant thuja is spring and late summer. Dense hedges can only be formed by regular pruning. Arborvitae are poisonous in all parts of the plant.
In which location do thuja plants feel most comfortable?
A sunny location is ideal for the conifers, partial shade is also possible. Full shade in the garden and on the balcony is unfavorable and the hedge plants only develop moderately. The uncomplicated plants thrive on both sandy and well-drained loamy soil. It is important that the soil is prepared appropriately when planting and that waterlogging never occurs. All arborvitae species thrive in weakly neutral, slightly alkaline and acidic soil; a pH value of 6 to 8 is ideal. Before planting Thuja, find out about the regulations on the local limit distances. This way you avoid unnecessary trouble. In some cases, there are also specifications in building regulations for the plants that may be planted as a hedge. In some areas Thuja plantings are not allowed.
When is the best thuja planting time and what is the best way to plant thuja hedges?
You can plant the conifers in pots all year round, provided the ground is not frozen. Some hedge plants with balls are offered in spring and autumn, these can only be planted for a limited period of time and require a little more care in the first year. With so-called container plants, you can plant the Thuja hedge all year round. Basically, all garden plants thrive best with sufficient soil moisture and warmth. Therefore, spring and late summer are the optimal Thuja planting time.
Applies to all Thuja species
- For soil that tends to compact, you can put a thin drainage layer of gravel or sand in the planting hole.
- Dig a planting hole twice as deep and wide as the root ball.
- First put 2 to 3 liters of potting soil in the planting hole.
- Water the hedge plants thoroughly before planting.
- Place the root ball in the planting hole and fill the cavity with a mixture of excavation and potting soil.
- Finally, sprinkle organic garden fertilizer on the surface and work it lightly into the soil.
- Finally, water the new planting with 10 to 20 liters of water, depending on the size of the hedge plant.
To avoid unwanted weeds, you can cover the freshly planted thujas with some mulch. This reduces evaporation of soil moisture and minimizes weed growth. Our gardening tip: Planting hedge shrubs is not recommended if the soil is extremely wet. Thuja Brabant or Arborvitae Smaragd are planted with 3 to 4 pieces per meter.
What is the best way to water Thuja plants?
Immediately after planting, it is important that you water the evergreen hedge plants evenly. Watering at longer intervals is recommended to stimulate the formation of new roots. With so-called need-based watering, additional water is added in phases without significant precipitation. Basically, larger amounts of water given at intervals help better than daily small doses. A watering of 10 to 20 liters once a week in the first year of planting can help the conifers to establish themselves at the new location. The amount of water varies depending on the temperature, soil conditions and size of the trees. The wood has only established itself in the second year and requires less attention. However, in years of extreme drought it may also be necessary
Our gardening tip: Make sure that the water is given directly to the trunk. A thin layer of mulch helps retain moisture in the soil and reduces evaporation throughout the year.
What is the best way to fertilize Thuja?
For a good development of the conifers it is important that sufficient nutrients are available. If there is no fertilizer, the structure is looser and the coloring of the needles is not as pronounced.
The first fertilization takes place in March/April with a special conifer fertilizer. This organic-mineral special fertilizer promotes growth and the natural color of the needles. Its high magnesium content prevents brown discoloration and enables lush green plants. Thanks to the organic components, nutrients are supplied over months.
A second application of natural fertilizer should be carried out in August/September. This natural biological fertilization promotes soil life and the formation of humus, which is beneficial for the health and vitality of the hedge plants.
Basically, it is important that the soil is evenly moist after fertilization.
Our gardening tip: Do not use complete mineral fertilizers and make sure that the nitrogen content is not too high with the second fertilization. Nitrogen stimulates growth and prevents the wood from maturing. The consequence of too high amounts of nitrogen is a reduced frost hardiness of the shrubs.
What is the best way to cut a tree of life hedge?
Trees of life are well tolerated by pruning and, as hedge plants, are pruned once a year if possible. A pruning from the end of June is optimal in order to remove the first growth, but also to give the wood enough time to regenerate before winter.
Important facts about hedge trimming
- Cut from the end of June to the beginning of September (in exceptional cases, you can also cut in early spring)
- Depending on the type of thuja and the intended use, it can be cut up to three times a year
- In summer it is important to note that the cut should only take place on an overcast day and if possible in a phase that is not too hot (this avoids burns).
- Only use sharp tools to shorten the shoots.
- Electric hedge trimmers are ideal for trimming hedges, and individual plants can also be trimmed with hand shears.
- Young thuja plants are not cut at all at first. You can shorten individual strongly growing branches with secateurs.
- Conical growth forms have proven their worth, the hedge is wider at the bottom and tapers more and more towards the top. The advantage here is that even in the lower area, enough light reaches the branches and snow is not deposited so easily.
- Do not cut too hard, because the evergreen cypress plants suffer from it.
- It is optimal if you remove 2/3 of the new growth when cutting.
Some species can also be cut into a ball or cone shape, making them attractive topiaries. The basic rule is: the more often you cut, the bushier and denser the coniferous tree grows. When cutting, make sure that you wear long clothes. The sap of thujas contains essential oils that are irritating and can lead to allergic reactions if they come into contact with the skin.
How do I plant thuja in tubs?
Even without a garden, you can plant the hedge plant on the balcony or terrace. Ideally, choose a Thuja species that is particularly well suited to pot culture or small gardens. These species are characterized by harmonious growth and good frost tolerance. Examples are Danica, Teddy or Tiny Tim. For good development, it is important that you choose a planter that is about twice the size of the root ball. Depending on the species, the tree can stand in the same pot for a few years or it may need to be repotted after 3 to 4 years.
It is important for thuja in a pot
- good drainage, fill expanded clay as the bottom layer in the planter
- Choose good quality potting soil for planting.
- Use organic garden fertilizer for planting.
- Keep the substrate evenly moist.
- Avoid waterlogging.
- Fertilize with liquid fertilizer every 4 to 6 weeks.
- Provide winter protection (for pots and shrubs).
Make sure that the evergreen wood needs even water even in winter and does not dry out completely. Our gardening tip: Conifers need an even water supply for a successful culture in the bucket. As an evergreen tree, such as bamboo or cherry laurel, the plant continuously evaporates water and, due to a lack of soil contact, no water can be supplied from the soil.
How to care for and winter thuja?
The popular hedge plant requires little care after rooting. Apart from even soil moisture, sufficient supply of nutrients and regular pruning, no further care measures are necessary. A thin layer of compost promotes soil life and prevents weed growth. Apply this layer of mulch in autumn and give the roots winter protection. Thuja planted in the ground is hardy and does not need special protection. In dry years, watering in November or spring may be necessary. As an evergreen tree, the species, unlike privet, evaporates all year round and is therefore more demanding in terms of soil moisture. It is important that you do not use road salt in the vicinity of Thuja hedges.
What types of thuja hedge plants are there?
There are five species in the Thuja genus, two of which are mainly grown in horticultural culture. The Occidental Tree of Life (Thuja occidentalis) is also known as the common Thuja and is often available as a hedge plant in the varieties ‘Smaragd’ and ‘Brabant’. Other species with spherical growth, dwarf forms or yellow needles enrich the range. The species Thuja plicata (or giant arborvitae) convinces with strong growth and is somewhat looser in structure.
Curious growth, special leaf structure
The availability of the species varies depending on the season, you will always discover new specialties in the range. You can also order hedge plants online. Especially in spring and autumn you can experience the large selection of coniferous trees.
What pests and diseases can thuja get?
With the right site conditions and needs-based fertilization, Thuja arborvitae are easy-care and healthy garden plants. Thuja plants that suffer from water stress, too much heat or a lack of fertilizer are more susceptible to diseases and pests. Here are some possible issues that may arise:
The Phytophthora fungus mainly attacks plants that are weakened and stand on compacted soil. The affected roots rot and the shoots turn pale yellow, later evenly brown until the plants die off completely. In hedges, only individual plants are usually affected, but it can spread quickly. Combating it is not possible, the only preventive measure is to prepare the subsoil sufficiently and avoid waterlogging.
Thuja miner moth
The twigs have browning from the shoot tips. In the event of an infestation, it is important to cut off the affected branches directly and strengthen the conifers with plant treatments. With optimal conditions and proper care, the damage will quickly heal, the trees will regenerate and you will have a beautiful hedge again.
In dry locations and in years with little rainfall, yellow discoloration of thuja hedges can quickly occur. This can be remedied quickly and easily through targeted watering.
It is important to act quickly here, because if there is waterlogging, the roots will rot and the plant cannot be adequately supplied. Try to eliminate the cause of the waterlogging and, if necessary, create a drainage layer.
Thuja often take on an even, rust-brown color in winter. This is a natural process. Especially with Thuja occidentalis and Thuja plicata this discoloration is present in winter. In the spring the hedge turns green again. The «Smaragd» variety is characterized by an even, fresh green color throughout the year and has quickly become a favorite in the garden.
Expresses itself with various symptoms and can be triggered by several factors. It is often fungal diseases that cause shoots to turn brown or yellow. Here it is important to cut off the affected shoots and use appropriate means to strengthen the plant.
Plant doctor – overview of conifers
Choose the type of damage that suits you best and find out more about the possible diseases your conifers could be infected with and what helps against them. Show overview of damage images
FAQ — Frequently asked questions about Thuja
What is suitable for combining with Thuja?
Thujen are attractive and opaque as a natural privacy screen. Possible partners for the combination can be, for example, other hedge plants such as privet, cherry laurel, boxwood, medlar or ornamental shrubs. It should be noted that thujas are flat-rooted, so a distance to flower beds and borders is recommended.
Which tree of life quickly grows into an opaque hedge?
With a growth of 30 to 40 cm, the Brabant tree of life is ideal for high hedges. It can also stand as a free-growing hedge for many years without pruning. However, without a cut, the leaf is not as dense. As a trimmed hedge, the species can be kept in good shape and the height can be set according to need. Brabant can reach several meters in height. Thuja occidentalis Smaragd grows slowly in the first few years and hardly needs pruning, some patience is required here, but the species remains lush green throughout the winter.