English elm belongs to the genus Ulmus and is a member of the Elm family (Ulmaceae).
English elm (Ulmus procera) is a deciduous tree growing to over 35m and flowering February to March.
Lifespan: can live over 100 years, with the oldest known examples reaching 400 years.
The bark is dark brown, rough and fissured. Suckers are produced freely from the base of the trunk. The twigs are short and hairy. Buds are ovoid, pointed and hairy. Leaves are round to oval, toothed with a rough, hairy surface texture (4–9cm) with very uneven bases at the leaf stalk: a familiar characteristic of all elms.
English elms are hermaphrodites: they have ‘perfect’ flowers with both sexes represented in one flower. Flowers hang in tassels, dark pink to red, and are produced before the tree comes into leaf. The fruits are tiny nutlets encased in the upper part of a thin, oval-shaped, papery wing but they are rarely produced. English elm is wind pollinated.
English elm is native to southern and eastern Europe. Despite its common name, it may only be native to southern England. It is thought to have been introduced by early colonisers.
Full-sized trees are attractive and majestic, and in the past they dominated the English countryside on rich farmland soils. They were also planted as an ornamental tree and have a number of subspecies and hybrids.
English elm is similar in form to wych elm (Ulmus glabra) our other native elm. Both species have similar human uses and wildlife value.
English elms were significantly reduced by Dutch elm disease in the 1960s and 70s which wiped out over 20 million trees. Now they are only found occasionally in hedgerows or woodland.
The heartwood of English elm is a dull brown colour; the sapwood is paler. Growth rings are irregular and the wood has a coarse texture. The timber is strong and able to resist strains which cause other timbers to split.
The timber can produce a good decorative veneer and has been used to make furniture, chair seats, wooden wheel hubs and, because of its ability to withstand saturation, water pipes, canal barges and boat keels. The leaves were shredded and used as cattle fodder.
English elm was planted extensively during the enclosure movement of the late 18th century. It became a popular hedge species due to its habit of growing and spreading from suckers. It was frequently coppiced and pollarded.
The artist John Constable frequently painted elms in his landscapes to capture the flavour of lowland England.
English elm can still be found as an important component of ancient species-rich hedgerows; which is a priority habitat under the UK Biodiversity Action Plan. Ancient hedgerows are mainly concentrated in the south and south west and around 4% of them may still be dominated by elm.
English elm does not have the wildlife value that our native oak trees have. However, many song birds and finches eat elm seeds and the leaves provide food for many insects, moths and butterflies.
The white letter hairstreak butterfly lives in the canopy of elms and suffered serious decline in the 1970s when Dutch elm disease reduced its food plants. This species has recovered in recent years. The large tortoiseshell and the Camberwell beauty butterflies suffered a similar fate and are now only seen as rare migrants.
Moth species such as the peppered moth, the light emerald and the white spotted pinion are also associated with elm species.
English elm is a light-loving species; it is only moderately tolerant of shade but is cold hardy. It is able to cope well with atmospheric pollution and salty winds near the coast. Best suited to fresh to moist soils of rich or very rich fertility. It is not suited to very dry or waterlogged soils or those of poor nutrient status.
Research is also ongoing in the genetic engineering of our elm species to make them resistant to the Dutch elm disease fungus. New varieties of elms have been grown by hybridising European elms with Asian varieties which have anti-fungal genes.
Both English and wych elms are susceptible to Dutch elm disease (Ophiostoma ulmi and O. novo-ulmi). Both elms need to be routinely cut back so they do not grow too large and attract the bark beetles that carry Dutch elm disease.
Elms can also be affected by galls from aphids which migrate from fruit cultivated trees (Schizoneura lanuginose, S. ulmi and Tetraneura ulmi).
Wych elm (Ulmus glabra) is also a member of the Ulmus genus. It is a deciduous tree growing to 40m and flowering February to March.
Wych elm is subtly different to English elm and the two species can be hard to tell apart. Their human use and wildlife value are very similar to English elm.
Wych elm has a greyish-brown bark with vertical fissures. Leaves are larger (7–16cm), oval to diamond-shaped with a more pronounced tapering tip, rough upper surface and an unequal base. The flowers are larger and paler than the English elm and the seeds are larger. The fruit nutlet is located in the centre of its oval papery wing. Wych elm reproduces by seed (root suckers are usually absent or sparse).
Wych elm is probably our most distinctive elm species being a large, spreading tree growing to around 40m. It is native to much of Europe and, being hardier than the English elm, enjoys a more northerly distribution growing well in the north, west and in parts of Scotland. It is the only elm that is regarded as being truly native to Britain.
Often found growing in hilly or rocky woodlands or beside streams and ditches; it favours calcareous soils.
Illustrations © Reader’s Digest Association, Inc.