Siberian elm and its cultivars are often used in landscapes where the tree is much appreciated for its hardiness and fast growth rate.
Siberian elm is a medium to large tree that can reach as much as 75 ft (22.5 m) in height. The tree is deciduous (tardily so in warmer climates), with leaves 1-3 in (2.5-7.5 cm) long. They are typical elm leaves, doubly toothed, and with uneven bases, although only barely so. The bark is rough and the branches tend to fork more than other elms. The little nondescript flowers appear before the leaves in early spring and the flat samaras, about a half inch (13 mm) across, in early summer. Several cultivars have been made available for resistance to breakage, increased cold hardiness, and differing habit, including a weeping selection ('Pendula'), and one that is bushier than the species: 'Berardii'.
Native to eastern Russia, northern China and Korea, Ulmus pumila, or Siberian elm, is a tree of the extensive mixed hardwood forests of the far north. It has been widely used in the American Great Plains as a street tree and in shelterbelt plantings.
Siberian elm is a fast growing, short lived tree with brittle wood that tends to break in ice storms. Young trees should be pruned to eliminate narrow crotches which will be particularly prone to breakage in later years. Light: Full sun is best for Siberian elm, which has very little tolerance for shade. Moisture: Siberian elm is quite drought tolerant, certainly more so than other elm species. Hardiness: USDA Zones 3-9. Siberian elm is said to be partially hardy even in Zone 2. Propagation: Propagate from seed. Named selections are grafted or started from cuttings.
The Siberian elm foliage is very similar to the other elm species.
Siberian elm bark
Its resistance to Dutch elm disease, and its cold hardiness and drought tolerance make Siberian elm a good choice for extreme northern landscapes and arid regions that have severe winters, such as the American Great Plains. It has been in cultivation as a street tree for several centuries, but its susceptibility to defoliation by leaf eating beetles and its tendency to break apart in ice storms make it less than desirable for most regions. Siberian elm does have a useful place in cross breeding with other elms to confer resistance to Dutch elm disease, an Asiatic fungus that has decimated American elms and many other elm species. Siberian elm is one of the parents of the elm cultivars 'Urban' and 'Regal', both of which are quite resistant to Dutch elm disease. Bonsai enthusiasts find Siberian elm to be a good subject for their craft.
In the Midwestern U.S., Siberian elm has become invasive in dry, open areas such as fallow fields, abandoned lots and railroad rights of way. Due to its high sunlight requirements it apparently does not invade native forests.
Siberian elm is sometimes confused with Chinese elm (Ulmus parvifolia), which is smaller, less cold hardy, and blooms in late summer. This is a pity, because the real Chinese elm is in almost all respects a much superior tree, this according to the distinguished American Plantsman, Michael Dirr and others.
Siberian elm trees are prodigious reseeders. In some regions this species is invasive and is disrupting native plant populations. Check locally before you plant this tree to determine if it is causing problems in your area.