Currently, a huge variety of decorative forms can “corner” even a specialist in coniferous plants, and their age variations and the presence of small (children’s) forms completely unlike adult specimens sometimes add a serious “headache” for dendrologists.
However, until now, in some garden stores, you can see one word on the labels — thuja. A sign with the name, for example, Oriental thuja or Korean thuja, can be considered a happy case. The importance of differences and the correct definition of thuja many people understand when they face completely different requirements for growing conditions.
Add fuel to the fire and the folded or giant thuja (Thuja plicata) with its forms, and the Korean thuja (Thuja koraiensis), which we will talk about separately in the next article. In the meantime, we will analyze the similarities and differences of the eastern platycladus and the Western thuja in order not only to easily distinguish them when meeting, but also to avoid mistakes when growing them.
Both monoecious coniferous plants of the cypress family Cupressaceae.
They often reach 4-10 m (13.1-32.8 ft) in height.
Both species have a pyramidal crown; Thuja often takes an ovoid shape with age. It is very similar to the Plaskovitsky young spherical western thuja.
Both have a large number of decorative forms, differing in height, appearance (habitus), and leaf color.
Both have great potential for use in your garden in single, group plantings, hedges, containers.
Both species tolerate both pruning and shearing well, so they are used for ordinary hedges. When planting, adhere to the following planting distances: in hedges – 40-50 cm (1.3-1.6 ft); in living walls – after 0.8-1.0 m (2.6-3.3 ft). As a result of the annual haircut for the 7th year, you will get a luxurious, rather dense hedge. Compact crowns of pyramidal-columnar forms of both types make it possible to create green walls practically without pruning.
It is surprising, but a fact – the similarity of these two species is manifested in common fungal diseases. So, in wet areas with stagnant spring melt water, the roots of thuja begin to brown and dry out from soaking. If the leaves turn yellow in the spring and are covered with a cobwebby mycelium that changes its color from gray to black, this is Schutte. The brownish upper part of both plants signals to summer residents – tracheomycosis or fusarium!
Both eastern platyclades (which is a coniferous medicinal plant of traditional Chinese medicine) and Western thuja have diuretic, antibacterial, sedative, anti-asthmatic, antipyretic, antitussive, expectorant, laxative, anthelmintic effects.
Thuja oil eliminates congestion and inflammation in the lungs. It also reduces the symptoms of destruction and stagnation in the pelvic organs (ovaries, uterus, prostate gland). Use as follows: bath – 3-5 drops, compresses – 3-4 drops, massage – 5 drops per 10 g (0.35 oz) of transport oil (base); 3-4 drops in the air sprayer.
Contraindicated during pregnancy and epilepsy; consult a doctor before use.
Platycladus orientalis – arid areas of Northern China and Iran.
Thuja occidental is the eastern part of North America.
The Western thuja is called the tree of life. The name of the American plant was given at the beginning of the XVI century by the king of France! At home, the Western thuja is better known as the American tree of life and the Northern White cedar. I believe that the tree of life is a translation of the popular name of one of the Asian species of thuja. The Western Indians built canoes from the root of the thuja tree.
The eastern platycladus branches upwards, branching from the base into several stems, which are apparently parallel to the main one. The branches are flat, radially located relative to the trunk, they form a kind of system of plates (hence the modern and most accurate name – platycladus).
Adult Western thuja is often single-barreled. The branches of the western thuja, unlike the platycladus, do not form plates; they are short, horizontal, their ends are directed upwards, and some are deployed from the trunk in different directions, creating a “curly” foliage surface.
The leaves of platycladus orientalis are scaly, rounded, with an oblong groove in the center of the upper body; arranged transversely, 1.5 mm (0.05 in) long, dull dark green, turn brown in winter; fit snugly to the trunk and lean on each other; have a specific aroma. They fall off after 3-5 years, after which the shoots become smooth, light brown.
The leaves of the Western thuja are flat with a round bulge (gland) on the central leaf, wedge-shaped scales (smaller than those of the platycladus) are glossy, turn brownish-green in winter; the upper side of the needles is green, and the lower one is evenly lettuce; very fragrant if the leaves are crushed!
The cones of platycladus are almost spherical, mature – red-brown or dark brown, with curved scales (“royal” cone, “core”, “horns”), 1.5 cm (0.6 in) long or more; they are formed annually, but bear fruit abundantly in 1-2 years.
The cones of the Western thuja are oblong, light brown or brownish-red, without “horns” – curved scales, 1-1.3 cm (0.4-0.5 in); abundant fruiting 1 time in 2-3 years.
Seeds of platycladus orientalis are oblong-ovate, brown, the size of a wheat grain, 0.5-0.8 cm (0.2-0.3 in) long; ripen in October – early November. High germination of well-treated seeds up to 100%! Before sowing, the seeds should be soaked in water for 24-28 hours. The depth of the seal is 5-6 cm (2-2.4 in).
The seeds of the Western thuja are flat, light brown, about 0.6 cm (0.24 in) long, with 2 wings. The seeds also have good germination in the soil – 80-85%! The sowing depth is 1 cm (0.4 in) or the surface followed by mulching.
Attitude to Soil
Eastern platycladus is salt-resistant, undemanding to soils, but grows best on loose forest soils. Having provided it with mineral fertilizers in the first 5 years after planting (early growth of shoots), you can forget about further fertilizing.
The western thuja is not demanding of the soil, it develops better on fertile, loamy, sandy loam and moist sandy soils (it does not tolerate drought).
Attitude to Sunlight
Platycladus orientalis is light-loving, but relatively shade-tolerant.
The western thuja is shade tolerant. All its forms can “burn out” in the bright spring sun! Therefore, it is important to protect it from direct sunlight with protective screens made of burlap.
Relation to soil moisture
Platycladus orientalis is drought-resistant, but responds well to watering; excessive humidity in winter is disastrous for it. In the first 3 years after planting, regular watering, then after 4-5 years – after the soil dries, and from 6 years – only in hot, dry summer.
The western thuja is less drought-resistant, so in the steppe zone it often replaces the more drought-resistant eastern platycladus.
Pruning and Transplanting
Platycladus orientalis tolerates transplanting well even in spring with an open root system. The deepening of the root neck is permissible, since at the same time additional roots are formed, and the plant becomes more wind-resistant in the future. Some gardeners use formative pruning, with gradual cleaning of the trunk from branches up to 50 cm (1.6 ft) high and removal of elongated apical shoots.
The western thuja grows slowly, with age the bark of its trunk becomes reddish-brown, cracked. Corrective pruning is applied to the thuja by shortening the branches, creating the desired contour, and then only sanitary with the removal of dead branches inside the crown. She is not afraid of the winds.
The Nuances of Reproduction
Platycladus orientalis is propagated by seeds (and decorative forms completely transfer their properties to offspring), cuttings.
Western thuja is also propagated by seeds (high-quality seeds are tied only when watered), but the seed progeny does not retain the decorative properties of the parent plants; decorative forms are only vegetatively, mainly by cuttings.