Watering red cedar

• Red cedar origin
• Red Cedar Care and Location
• Cutting red cedar
• Fertilizing red cedars
• Watering red cedar

Red cedar origin

The red cedar (Thuja plicata), also known as the giant arborvitae, western red cedar, or western thuja, is an imposing evergreen conifer in the cypress family (Cupressaceae). Its native range is along the Pacific coast of North America, particularly in the coastal regions of British Columbia (Canada), as well as the US states of Washington, Oregon, California, and southeastern Alaska. There, it is the dominant tree species in the temperate rainforests, which are characterized by a humid, mild climate and impressively diverse vegetation.

The red cedar is one of the tallest tree species in North America and, in its natural habitat, can reach heights of up to 70 meters and trunk diameters of over 5 meters. The oldest specimens are estimated to be over 1000 years old. The red cedar grows with remarkable vigor, particularly in humid coastal regions. There, the tree species thrives on nutrient-rich, deep soils and benefits from the oceanic climate with high humidity and mild winters.

For the indigenous peoples of Northwestern America, including the Haida, Tlingit, Salish, and Tsimshian, the red cedar held central cultural and practical significance. It was used not only for construction but also revered as a spiritual and sacred tree. The wood was used to make totem poles, canoes, longhouses, masks, and ritual objects. The bark was processed into clothing, mats, and rope. To this day, it plays an important role in the mythology and identity of these cultures—many call it the "Tree of Life."

The red cedar arrived in Europe in the mid-19th century. It was first introduced in England as an ornamental tree and gradually spread throughout Central Europe. In Germany, it has been found in parks, gardens, and cemeteries since the early 20th century, primarily as a hedge plant, windbreak, or specimen tree. It is valued for its dense growth, decorative foliage, and good tolerance to pruning. Its resinous, spicy fragrance makes it even more popular, as does its evergreen appearance, which brings structure and color to gardens even in winter.

Although the name "red cedar" suggests otherwise, botanically it does not belong to the true cedar family (Cedrus genus), but rather to the arborvitae (Thuja), a genus within the false cypress family. Its wood is lightweight, resistant to rot and insect attack, and is still widely used today—for example, for exterior cladding, roof shingles, sauna construction, and musical instruments. In North America, Thuja plicata is an important economic factor in the forestry industry.

Care and location

The red cedar is an easy-care and robust garden plant, suitable both as a specimen tree and as a hedge. It prefers a sunny to partially shaded location. While it will also grow in fully shaded areas, it tends to have a looser, more sparse growth pattern. Its characteristic dense growth develops best in good light.

The red cedar is adaptable in terms of soil, but prefers deep, humus-rich, and moderately moist soils with good drainage. Loamy, slightly acidic to neutral substrates are ideal. It suffers from water shortages in dry, sandy soils, while waterlogged soils can damage the roots. Therefore, the location should be well-drained. Amending the soil with compost or bark humus is recommended for heavy soils.

In its early stages, the red cedar requires some frost protection, especially in windy or exposed locations. Mature plants, however, are winter hardy in Central Europe. A layer of mulch around the root zone regulates soil moisture and protects the sensitive shallow roots from extreme temperatures. Mulch also reduces weed growth and promotes soil life.

Individual specimens should be planted at a sufficient distance from buildings and other trees, as the red cedar can reach a considerable size. However, when grown as a hedge, it can easily be controlled in height and width. Overall, the Thuja plicata is one of the most resilient woody plants in the garden—it even tolerates air pollution and urban climates relatively well.

Cutting red cedar

The red cedar tolerates pruning very well and can be shaped without any problems. Regular pruning is particularly beneficial as a hedge plant. pruning necessary to maintain a dense, uniform structure. The best time for pruning is between late summer and early autumn (August to September), as growth is largely complete by then and the cut surfaces can become woody before winter.

In spring, light shaping pruning is possible before new growth begins. However, it's important not to cut too deeply into the old wood, as the red cedar has difficulty regrowing from leafless sections. Brown, needleless areas are often found, especially in the interior of the tree—cutting into these areas will leave permanent bald patches.

For hedges, a slightly conical pruning shape is recommended—narrower at the top, wider at the bottom—to ensure even light distribution. This ensures the plant remains evenly covered from top to bottom. Individual trees generally only require occasional maintenance pruning to remove dead, damaged, or crossing branches.

Clean, sharp tools are essential when pruning to avoid bruising. Cut surfaces on thicker branches can be treated with a wound closure product to prevent infection. In strong sunlight, pruning should be done on overcast days to avoid sunburn on the exposed parts of the plant.

Fertilizing red cedars

A regular fertilization Supports the growth of the red cedar and promotes health and the intense green color of the needles. Organic or organo-mineral slow-release fertilizers applied in spring (March to April) are ideal. Horn shavings, compost, or special conifer fertilizers with a balanced NPK ratio (e.g., 10-5-8) are particularly suitable.

For hedges, especially on nutrient-poor soils, fertilization should be done annually. Potted plants require a liquid fertilizer every two to four weeks during the main growth period (April to August), as the container has a limited nutrient reservoir. An additional Mulch cover made from bark humus or pine bark maintains the soil structure and acts as a natural long-term fertilizer.

From late summer (end of July), nitrogen-rich fertilizers should no longer be applied to avoid unnecessarily prolonging shoot growth. Instead, potassium-rich fertilizers are recommended, as they strengthen cell structure and increase frost resistance. Overfertilization should be avoided, as this weakens plant tissue and makes it susceptible to disease.

Watering red cedar

In the first years after planting, the red cedar requires regular, penetrating irrigationThe soil should be consistently moist, but never waterlogged. Especially in young plants and newly planted hedges, the root system is not yet sufficiently developed to survive dry periods. Therefore, regular watering is recommended, especially during the summer months – once or twice a week, depending on the weather, with 20–40 liters per plant.

Older specimens are significantly more drought-tolerant, but also benefit from additional watering during hot periods. A good rule of thumb: Water infrequently but thoroughly. A watering rim or watering rings help direct water directly to the root zone. Watering bags are a practical solution for larger specimens or hedges.

The best time to water is in the morning or evening, when evaporation is low. Watering can also be done in winter during periods of prolonged drought—especially during frost-free periods to prevent the evergreen needles from drying out (frost drought). It's important to check the soil moisture level before each watering to avoid waterlogging.

A mulch layer of bark humus, grass clippings, or leaves protects the soil from drying out and reduces the need for watering. During hot periods and long dry periods, the red cedar should not be left unattended—its otherwise robust appearance can quickly suffer from a lack of water.

In general, there are Watering trees There are some general guidelines to follow. Here are the most important points:

• If a tree isn't in a pot but is planted directly in the ground, you should water it plenty at once. The ideal amount per watering is between 75 and 100 liters. This ensures that the water actually reaches the tree's root area.
• The water should be released as slowly as possible so the soil can absorb it. If the water is applied too quickly, it will run off the surface, as dry soil can only absorb a small amount of water. Therefore, we recommend using tree watering bags.
• The baumbad watering bags They release water drop by drop into the soil through small holes over a period of several hours. This ensures even soil moisture throughout the entire root zone, allowing the roots to absorb the water well.
• The watering bag is placed around the tree trunk like a jacket and zipped shut. The next step is to fill the watering bag with water and then allow it to drain drop by drop.