Description

Ulmus – Elm

This genus is comprised of 45 deciduous, rarely semi-evergreen trees and very rarely shrubs.  Most elms are large limbed trees forming a domed crown with furrowed or fissured gray bark.  There found natural occurring in woodland, thickets, and hedgerows in the northern hemisphere and Siberia to Indonesia, Mexico to Japan.  They have alternate, ovate to elliptic, egg shaped or rounded leaves with prominent, parallel lateral veins and may be single or double toothed margins and with unequally sized bases. The leaves usually color to yellow in autumn.  Cluster of tiny, bell shaped flowers, each with 4-9 segments joined at the bases, are usually produced from auxiliary buds in spring, but sometimes from leafy buds in autumn, they are quickly followed by green to brown, rounded to elliptic, membranous wing seed capsules.  Cultivated for their habit and foliage, elms’ are mainly grown as specimen trees.  Ulmus x hollandica ‘Jacqueline Hillier’ is suitable for shrub border and for hedging. In areas free of Dutch elm disease grow in any well-drained soil in full sun or partial shade.  Zelkovas are good substitutes where Dutch elm is prevalent. Prone to Dutch elm disease caused by the fungus Ophiostoma Ulmi spread by bark beetles and natural grafts, has destroyed hundred of thousands of American elms.  There has been recent breeding between European and Asiatic species that are slowly showing more resistant to the disease. They are also prone to Borers, Beetles, Caterpillars, mealy bugs, scale insects, leaf hoopers, mushroom root rot, dieback, canker, Verticillium wilt, wood rot, lepidopteran larvae, hepialid moth, phloem necrosis, and elm yellows. U. Americana – American Elm – White Elm – Water Elm – This elm is the largest North American elms found natural occurring in Eastern and central North America, where it can reach up to 120 feet and a 100 feet wide. This vase shape deciduous tree bears ash gray bark that is deeply fissured and reach 4’ feet in diameter and the branch tips tend to be pendulous. It produces alternate ovate to elliptic, double toothed dark green leaves 4-6” long, and have a smooth upper surface with a slightly downy underside. The leaves turn bright yellow in autumn. Tiny, hermaphrodite, purple brown petalless flowers are borne in early spring followed by samara winged green fruit, ½” across. In areas free of Dutch elm disease grow in any well-drained soil in full sun or partial shade. Zelkovas are good substitutes where Dutch elm is prevalent. zones 3-9