A robust small tree with fantastic autumn colours
Henrik Sjöman and Andrew Hirons
Among Asian maples there is an amazing diversity of expression – from shrubs to large trees, often with exciting leaves, trunks and seasonal qualities.
One of the more unusual species is the Tschonoski maple (Acer tschonoskii), which in cultivation in arboretums and botanical gardens has proven to be very beautiful and robust. It would therefore be a very interesting addition to try in more public contexts as well.
The Tschonoski maple originates from Japan where in nature it develops into a smaller tree that usually becomes multi-stemmed and up to 12 metres high, while in northern European cultivation it usually develops into a medium-sized shrub. Taxonomically, the species belongs to the group of striped maples, but it lacks the characteristically striped trunks and is distinguished by the strictly upward-pointing inflorescences. Instead, it is more closely related to Acer komarovii, which in some literature is considered to be the mainland type of the Tschonoski maple and is described as Acer tschonoskii ssp. koreanum (syn. Acer tschonoskii var. rubripes). This is distinguished by deeper-lobed leaves and more or less clearly red annual shoots. The mainland type of the species is also described as being more cold-hardy.
In European cultivation, the Tschonoski maple develops into a wide-growing, multi-stemmed tree, 2–4 (max. 6) metres high and almost as wide. When young, it has a distinctly upright, vase-shaped growth pattern but becomes wider with slightly overhanging growth as it ages. The leaves are five-lobed with an elongated central lobe, 5–10 cm long with a glossy green surface and a lighted underside. Autumn colours are usually yellow with hints of purple. Some individuals of the inland type can have intense rose-red autumn colours. The yellow-green, upright inflorescences are much appreciated by nectar-gathering insects and when the species blooms, the air is often full of butterflies, which have given the species an additional name – butterfly maple.
The species is continental in its personality and emerges early in the spring and thus risks being damaged by late spring frosts – from which it usually recovers. Cool spring locations that do not promote premature bud burst are therefore preferable. However, the ability to start too early in the spring seems to decrease with age: older plants have a better chance of coping with a late cold snap. Otherwise, the species is very reliable, robust and hardy. It would be a very interesting addition to the palette of reliable maples for private and public green environments.
With the mainland variety, you can find really beautiful specimens with intense red shoots, which enhance their ornamental quality in winter. The species requires cool and moist conditions for successful development, but can handle short periods of drought without suffering extensive damage.
The Tschonoski maple develops into a smaller tree, usually with a multi-stemmed expression.
In the mainland type of the Tschonoski maple (Acer tschonoskii ssp. koreanum) there are types with intense rose-red autumn colours.
In summer the Tschonoski maple’s leaves are a beautiful green but the leaf stalks usually have a reddish colour, which creates a nice contrast.
Dr Henrik Sjöman is a Lecturer at the Swedish University of Agriculture Sciences and a Scientific Curator at Gothenburg Botanic Garden.
Dr Andrew Hirons is a Senior Lecturer in Arboriculture and Urban Forestry at University Centre Myerscough.
This article was taken from Issue 203 Winter 2023 of the ARB Magazine, which is available to view free to members by simply logging in to the website and viewing your profile area.