Watering Thuja, Tree of Life

The Thuja, also known as the arborvitae, belongs to the cypress family (Cupressaceae) and includes several species native to North America and East Asia. Introduced to Europe in the 16th century, the Thuja quickly became a popular ornamental and hedge plant. 

In its natural habitat, the Thuja prefers moist, densely wooded areas. Thuja occidentalis is native to eastern Canada and the northeastern United States, while Thuja plicata originates from the rainforests of the Pacific Northwest. Under optimal conditions, the giant Thuja can grow over 50 meters tall. Here in Central Europe, however, it remains significantly smaller, usually between 4 and 15 meters.
The German name "Tree of Life" refers to the symbolism of evergreen plants, which represent stability, vitality, and protection. Thuja has also been used in folk medicine since ancient times, for example, as a homeopathic remedy or as an ingredient in incense blends. Botanically speaking, the Thuja is a coniferous tree with scale-like foliage and small cones, particularly valued for its dense, uniform growth habit.

Thuja care and location

The Thuja is an easy-care tree, but it does have certain requirements regarding location and soil. A sunny to partially shaded location is ideal. While the Thuja also tolerates shady areas, its growth is usually less dense in these locations. 
The soil should be fresh to moist, nutrient-rich, and well-drained. Waterlogging is poorly tolerated. Persistently dry or sandy soil is equally problematic, especially for young plants. A humus-rich loamy soil that retains moisture but is also well-drained is ideal.

Once established, the Thuja is resilient to many environmental factors: wind, frost, and urban climates generally pose no problems. However, it is sensitive to salt, such as road salt in winter. Frost combined with winter sun can also lead to drought damage, as the needles evaporate water without any replenishment from the frozen ground. Young Thujas, in particular, therefore benefit from light winter protection such as fleece or brushwood.

Cutting Thuja

Thuja tolerates pruning extremely well and should be trimmed regularly, especially if planted as a hedge. Without regular pruning, the plant can become bald at the base and lose its dense, compact growth habit.
The best time for a pruning is late spring (May to June) after the first shoots appear. A second cut can be made in late summer (August). It is important to only cut into the green, young wood. If you cut too deeply into the old, woody interior of the plant, the thuja will usually not sprout again there. Therefore, you should proceed carefully when pruning and maintain a uniform shape as much as possible.

For a dense and healthy hedge, a conical cut is recommended: wider at the bottom than at the top. This allows more light to reach the lower branches, promoting even growth. Clean, sharp hedge trimmers prevent damage to the shoots. Pruning should not be done on very hot or frosty days, as the plant is particularly sensitive during these periods.

Do you need to fertilize thujas?

Although the Thuja is considered relatively undemanding, targeted fertilization improve growth and resistance to diseases and environmental influences, especially on nutrient-poor soils. 
In spring, ideally in March or April, an organic slow-release fertilizer or a special conifer fertilizer can be applied. On particularly sandy soils, a second application in June is recommended. Fertilization should be discontinued after late summer to avoid disrupting the ripening of the shoots before winter.
Organic fertilizers such as horn shavings, compost, or bark humus are particularly suitable because they not only provide nutrients but also improve soil structure. It's important that the fertilizer isn't applied directly to the trunk, but rather worked into the outer root area. The circumference of the tree crown provides a good guideline for this. 
Signs of nutrient deficiency include pale green or yellowish needles and overall sparse growth. A soil analysis can provide clarity and help determine appropriate fertilizer recommendations.

Water Thuja properly!

Thujas require regular and thorough watering, especially in the first few years after planting. Adequate irrigation is crucial for the plant's health, especially during long dry periods, which are becoming increasingly common due to climate change.
Young plants need to be well cared for in the first two to three years after planting, as they have not yet developed a deep root system. The rule is: water less frequently but thoroughly. GiessenIdeally, the soil should be moistened so that the water penetrates deep into the root zone. Superficial watering often only leads to evaporation without actually nourishing the plant.

The best time to water is morning or evening. Waterlogging should be avoided at all costs, as it can lead to root rot. The soil should dry out slightly between waterings, but not completely. 
In case of visible drought stress – for example, yellow, brown or curled needles – quick action is required. In such cases, a Irrigation bag, such as the one offered by baumbad, can be very helpful. This releases the water drop by drop over several hours, allowing the roots to absorb it effectively. At the same time, evaporation is minimized and water is saved. This is a useful addition to the traditional watering method, especially for young thujas or for plantings on slopes or in sandy soils.