Ailanthus altissima Purple Dragon

IMPORTANT: for the preservation of our natural ecosystems, we have removed this plant from our catalogue as it is considered invasive. Therefore, it is no longer available for sale.

Ailanthus altissima Purple Dragon is a variety of the glandulous Tree of Heaven with a strongly exotic appearance that stands out in spring, with its young red shoots unfolding into beautifully coloured purple leaves. Its leaves develop while gradually becoming light green and fuzzy, while the tree produces its flowers in early summer, in the form of fine upright panicles, of a yellowish-green colour. Only the female plants, in the presence of male plants, produce reddish fruits that remain on the branches long after the leaves have fallen. This large deciduous tree with rapid growth requires space and has a tendency to sucker.

Ailanthus altissima Purple Dragon, or Tree of Heaven, belongs to the little-known family of Simaroubaceae, which includes 50 species grouped into around twenty genera. Members of this family are shrubs and aromatic trees, characterised by the presence of organic compounds called terpenoids in their tissues, whose properties are used in herbal medicine. In Ailanthus altissima, these molecules are responsible for the particular odour that emanates from all parts of the plant, especially when the foliage is crushed. This aroma, which may be unpleasant, is often compared to that of peanuts. It was first introduced to France for silkworm breeding.

Ailanthus altissima is a large deciduous tree that is extremely ubiquitous and native to Asia, specifically northern and central China, Taiwan, and northern Korea. It is now present in many countries around the world, where it is sometimes considered invasive. Ailanthus altissima is a dioecious species, meaning that male and female flowers are present on separate individuals.

'Purple Dragon' is a superb cultivar with purple foliage derived from this species. With rapid growth, especially in moist soil, it reaches a height of about 8 m (26 ft 2 in) in ten years and a height of 20 to 25 m (65 ft 7 in to 82 ft) at maturity, with a spread of 10 to 12 m (32 ft 10 in to 39 ft 5 in). This tree consists of a trunk, often branched near the base, topped with a rounded and spreading crown. The bark covering the trunk is grey and smooth, often becoming slightly rougher and fissured on an older specimen. The sturdy branches have smooth to slightly pubescent bark, red in colour. In spring, the branches develop young red shoots. These young shoots unfold into leaves that can reach a length of 90 cm (35.4 in), divided into 11 to 41 elliptical leaflets arranged in pairs, and purple in colour. The leaves then turn more or less green or violet. Flowering takes place in April-May in warm climates, and in June-July elsewhere. At the end of the shoots, upright inflorescences develop, composed of small green to cream-coloured flowers. After pollination by various insects, the flowers produce fruits that resemble maple samaras. These clusters of fruits, initially green, then turn a beautiful red-pink colour. The seeds have the ability to germinate very quickly when favourable conditions are met. Note that this Tree of Heaven is capable of adapting to almost all growing conditions. In nature, it is found from arid regions to very humid and cold regions. The mature tree only fears shade and waterlogged or overly acidic soils. Its lifespan is around 50 years.

The Purple Dragon Tree of Heaven is a beautiful tree, with an exotic appearance that will be highlighted when planted alone in a large garden. Able to thrive in neglected areas abandoned by other plants, it is valuable in a dry garden, in degraded soil, but also in urban areas where it tolerates pollution very well. It will express all its uniqueness as a shade tree or specimen.

Important to know:

The strong roots of Ailanthus altissima secrete allelopathic substances that inhibit the germination and growth of neighbouring plants. When the trunk of this tree is cut, it easily regrows from the stump by forming suckers. The roots, capable of damaging the foundations of buildings or nearby pipelines, also have the ability to produce new plants at a distance from the parent tree. It is therefore a potentially invasive species, and its development and multiplication must be strictly controlled.