Thuja Occidentale

Class

Pinopsida

Division

Pinophyta

Family

Cupressaceae

Order

Pinales

Genus

Thuja

Species

occidentalis

Description

Elegant-looking tree, medium to large in size when mature. Slender habit with a compact, almost columnar conical crown and close branching. It has scaly, shiny green leaves with golden highlights; flowers discreetly and not very ornamental in spring. The reddish-brown bark peels off in strips. Solid rooting, medium deep and widespread in the soil. Very hardy, adapts to climatic variations, even in urban climates and parks. It prefers clay and sandy, drained soils but grows well in all soil types.
It belongs to the coniferous group that lends itself to widespread, multifunctional, ornamental and landscape use. Resistant to disease, it does not require pruning. It must never be topped or pruned. Includes many varieties with different foliage colours.

Curiosities and special features

The Western Tuia in America is commonly called 'Arbor vitae' or Tree of Life.

Origin and distribution

A botanical species native to a range extending from east-central Canada to the north-central and eastern United States, it was introduced to Europe in the 1500s as an ornamental plant.

Leaf

The leaves, evergreen and appressed to the twigs, have a scaly lamina.

Leaf colour

Homogeneous, bright green shade with golden highlights.

Plant height

The height of the plant varies from 1 to 20 m, depending on cultivation conditions.

In general, the Western Thuja is a second-sized tree.

Lifespan

Evergreen perennial conifer.

Where to plant

It lends itself to widespread and multifunctional use, making it suitable for flowerbeds, gardens and parks, open fields, hedges.

Suitable for medium to large green areas in isolated form or in small groups, and also for the formation of trees in rows, both in parks and on roadways but applying the right distance from carriageways.

Stem

The stem is woody with reddish brown bark that peels off in vertical stripes; the variety has no thorns.

Flower

The flower is simple in form, small in size, with a globular corolla. The petals are single-coloured. It flowers from early to mid spring, with a flowering period of between 15 and 20 days. It is not particularly attractive to pollinating insects.

Growth

Medium-vigorous Growth plant.

Plant habit

The developed vegetative habitus is erect, slender with a compact, almost columnar conical crown.

Branching

Branching is abundant and close together.

PH

It requires a soil pH between 6.0 and 7.0.

Soil preparation

Before transplanting at the end of autumn, choose the most suitable location, depending on the needs of the plant, and use a spade to make the planting hole at least one third larger than the volume of roots or root ball to be transplanted.

Remove any weeds and bulky pebbles.

Sun exposure

Suitable for exposure in bright shade, full sun.

Ideal climate and temperature

The ideal temperature is between 0.0 and 30 °C. It adapts well to cold winter climates as well as warm summer climates.

Use

Widely appreciated for its plant architecture as a conifer in:
Outdoor ornamental Outdoor Landscape Design Landscaping

Hardiness

With itshigh rusticity, it adapts to different soil and climatic conditions, even in urban areas, after correct planting in the new site. It is also resistant to numerous phytopathologies.

Soil

It prefers a medium-textured soil with organic matter and good drainage but adapts to different soil types.

Difficulty

After proper establishment following transplanting, Western Thuja is fairly easy to grow, requiring a medium level of maintenance.

Growing tips

Some useful and specific cultivation tips:
Balanced fertilisation Expose the plant to maximum light Plant that adapts very well to cold winter climates and also thrives in frozen soil conditions.

Planting

Choose healthy specimens, free from abiotic and biotic stress conditions. Always identify the planting site in advance in relation to the growth conditions required by the species according to the principle 'the right plant in the right place'.

When transplanting, spread the root ball well in fresh, loose soil. If the plant was previously grown in pots, thin out the roots a little and enlarge the lower part. If necessary, cut off the bottom part of the root ball with a box cutter to help the root ball develop in width. Transplant by completely burying the root ball.

Pruning

It is a plant that does not require pruning but only minor volume reduction in the case of interference with buildings. It must not be topped or pruned.

Propagation

Propagation can be by seed and by cuttings. Micropropagation is very common.

Watering

At transplanting keep the soil compact in temperate conditions, avoiding excessive watering with stagnation. Allow the soil to dry out slightly between one watering and the next after planting, but prevent dryness. It is advisable to avoid water-saturated conditions and to apply quantities with frequencies and doses that are also commensurate with the climatic trend during the different seasons.

Fertilising

During soil preparation, perform a background fertilisation, then intervene at least once a year, during the spring or autumn period, by evenly distributing a specific slow-release balanced fertiliser to the soil.

Edibility for humans

Non-edible

Toxicity for humans

Toxic

Tip

During cultivation, light training pruning is carried out to determine the structure of the plant by shaping the shape of the foliage (oval or conical).