Ulmus (Elm)
A classic, deciduous hedgerow tree, which succeeds in almost any soil and situation. Sadly, due to the advent of Dutch Elm disease very few native elms now survive in the UK. The majority of Ulmus species grow too large for the average sized garden but a number of compact, disease resistant, varieties may be suitable for larger gardens.
Family: Ulmaceae
Botanical Name: Ulmus
Common Names: Elm
Foliage: Deciduous, oval, toothed green leaves. Generally good autumn colour.
Blossom: Small flowers, followed by small green winged fruits.
Flowering Period: Mid to late spring.
Soil: Well-drained soil (clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or partial shade, in an east, west or south facing aspect.
Habit: Tall, bushy, fast growing.
Type: Large tree.
Origin: Europe
Hardiness: Fully hardy in the UK.
Planting and Growing Ulmus
Plant in any well drained soil in full sun or partial shade. Grows best in good, deep rich soil, where it will be less subject to pests and diseases. Most species have good resistance to pollution.
Compact forms make an excellent specimen tree for a lawn.
Taking Care of Ulmus
Pruning
Not necessary, except to remove any unwanted, damaged or diseased branches in autumn.
Pests and Diseases
Susceptible to attack by aphids, bark beetles, horse chestnut scale and elm gall mites. Can be affected by coral spot, honey fungus and phytophthora.
Most species are susceptible to Dutch Elm Disease, caused by the fungus Ophiostoma novo-ulmi, which is spread by elm bark beetles. It is a devastating disease that causes rapid yellowing of foliage, wilting, shriveling and eventual death of the tree. Dead trees are a safety hazard and should be felled promptly.
Propagating Ulmus
It is best to buy fresh stock from a reputable supplier and choose only disease resistant varieties, such as Ulmus 'New Horizon'.
Heritage Varieties of Ulmus
Ulmus glabra (wych or Scotch Elm) forms a large graceful green tree. The foliage turns a pleasing yellow in autumn. Height to 100ft (30m), spread 40ft (12m). Variety 'pendula' (weeping wych elm) is a dome shaped tree with stiffly pendulous branches. Height to 25ft (8m), spread 20ft (6m). The cultivar 'Camperdownii' (Camperdown elm) is another compact weeping form. Height and spread to 25ft (8m).
Ulmus major (Dutch elm) is a native elm, similar in stature to the common elm but with a much more open, spreading habit and the larger leaves. Height 100ft (30m) or more.
Ulmus minor (Ulmus nitens, field elm) forms a fine tree, pyramidal when young, becoming more pendulous-branched with age. Height to 100ft (30m). The leaves are smaller than those of most other species. Pendulous and variegated varieties are available.
Ulmus parvifolia is a compact elegant tree, which often retains its green foliage until well into December. Height to 40ft (12m).
Ulmus procera (English elm) is a large impressive tree found mainly in the south of England, where it was once common in hedgerows. The leaves have a reddish tinge early in the year. Sucker-producing roots. Height to 130ft (40m).
Ulmus vegeta (Huntingdon elm) is a hybrid raised at Huntingdon in 1836. Forms a large tree with a short, thick trunk and exceptionally vigorous in growth.
Ulmus viminalis (twiggy field elm) forms an elegant, slender, small-leaved elm with pendulous leafy branches. Height to 30ft (9m).