Introduction
An excellent tree that is surprisingly under-used, Chinese elm possesses many traits which make it ideal for a multitude of landscape uses. A fast-growing, nearly evergreen tree, 'Drake' Chinese elm forms a graceful, spreading, rounded canopy of long, arching, and somewhat weeping branches which are clothed with two to three-inch-long, shiny, dark green, leathery leaves. Some specimens grow in the typical vase-shaped elm form, others appear to grow horizontally instead of upright like a tree. In the cooler part of its range in fall, leaves are transformed into various shades of red, purple, or yellow. The tree is evergreen in the southern extent of its range. The showy, exfoliating bark reveals random, mottled patterns of grey, green, orange, and brown, adding great textural and visual interest, especially to its winter silhouette. The Chinese elm species can reach 80 feet in height but this cultivar probably grows to about 40 to 50 feet tall. It makes an ideal shade, specimen, street or parking lot tree, provided it is trained and pruned to allow for vehicular and pedestrian clearance below. They look very nice planted in a grove or along a street.
Credit: Ed Gilman, UF/IFAS
General Information
Scientific name: Ulmus parvifolia
Pronunciation: UL-mus par-vih-FOLE-ee-uh
Common name(s): 'Drake' Chinese elm, 'Drake' lacebark elm
Family: Ulmaceae
USDA hardiness zones: 7B through 10B (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: sidewalk cutout (tree pit); reclamation; urban tolerant; street without sidewalk; shade; specimen; parking lot island < 100 sq ft; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; tree lawn 3-4 feet wide; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; highway median
Availability: not native to North America
Description
Height: 35 to 45 feet
Spread: 35 to 50 feet
Crown uniformity: symmetrical
Crown shape: weeping, round, vase, spreading
Crown density: moderate
Growth rate: moderate
Texture: fine
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: serrate, serrulate
Leaf shape: obovate, elliptic (oval), ovate
Leaf venation: pinnate
Leaf type and persistence: semi-evergreen, evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: yellow
Fall characteristic: not showy
Flower
Flower color: green
Flower characteristics: not showy
Fruit
Fruit shape: oval
Fruit length: less than .5 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; showy; typically multi-trunked; thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: gray, brown
Current year twig thickness: thin
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun, or partial shade
Soil tolerances: sand; loam; clay; acidic; alkaline; well-drained; occasionally wet
Drought tolerance: high
Aerosol salt tolerance: moderate
Other
Roots: not a problem
Winter interest: yes
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: susceptible
Pest resistance: resistant to pests/diseases
Use and Management
Select trees with branches spaced along one trunk. It is not essential that this trunk be straight. Buy from nurseries who understand how to train and prune this tree for street and parking lot use, otherwise you may be trimming and pruning low drooping branches on a regular basis.
Trees which have a trunk less than about two inches in diameter often require staking and some early pruning to prevent leaning and blowover due to a heavy crown and unstable root system. Nursery operators often train trees to a single, straight trunk by staking at an early age. Leave branches on the lower trunk during this training period to encourage caliper development on the lower trunk. Older trees look nice with an occasional light thinning to show off the wonderful trunk and branch structure.
Be sure that the trees you purchase were propagated from cuttings. If not, you may not be buying 'Drake' elm. Please do not confuse it with Ulmus pumila, the Siberian elm. Siberian elm is far inferior to Chinese elm and should not be planted, except perhaps in extreme climates where the limits of most other trees are tested.
Chinese elm is sometimes topped in the nursery to create a full head of foliage and branches originate from one point on the trunk. There is not enough room on the trunk to support this type of branch structure, and some may split out from the tree as it ages. This tree may take more effort to properly train and prune when young than some other species but it is well worth the effort. It will have a long service life in urban areas with proper training early on.
The root system is comprised of several very large-diameter roots which can grow to great distances from the trunk. These are usually located fairly close to the surface of the soil and can occasionally lift sidewalks. They can get into sewer lines causing damage. But they are usually not a problem and should not be cause to eliminate this tree from your urban tree planting program. This is among the top urban trees on most recommended tree lists in the south and midwest. Although it appears to tolerate urban conditions very well, trees in wet soil can develop a trunk canker which can kill the tree. Young trees are affected more often than older, well-established specimens.
Chinese elm will grow in full sun on a wide range of soils, adapting easily to extremes in pH (including alkaline) or moisture, and tolerates cold, urban heat, and wind. Trees will look their best, though, when grown in moist, well-drained, fertile soil but they adapt to drought and the extremes of urban sites. Very suitable for street tree pits, parking lot islands, and other confined soil spaces.
Many cultivars are available for size and form: 'Catlin' is dwarf; 'Drake', USDA hardiness zones 7 to 9, has small, dark green leaves, sweeping, upright branches forming a rounded crown, and greater leaf retention being almost evergreen in California and Florida; 'Dynasty' has smooth, dark grey bark, smaller leaves and is vase-shaped, with red fall color in the north; 'Frosty' has a small (0.75-inch-long), white-margined leaf which may revert back to green; 'Emer I' has a dark green, fine-textured uniform crown comprised of ascending branches with bright orange, grey and brown exfoliating bark. It is a brand new introduction and the parent tree is reportedly 50 years, 32 feet tall and 54 feet wide; 'Golden Rey' is reportedly hardy to USDA hardiness zone 6, is a moderate grower and may be denser and more compact than the species. This cultivar was selected for its yellow new foliage color which deepens to golden yellow in autumn; 'Pathfinder' has been extensively tested in Ohio for 30 years (USDA hardiness zone 5a). It has a single trunk with broad, upright branches and grows at a moderate height. Bark is nicely exfoliating, fall color is a rich red and this National Arboretum/Ohio Research Site introduction tolerates wet and dry soil. A good tree for tough sites; 'Sempervirens (Pendens)' is more round-headed, weeping and spreading with persistent foliage, almost evergreen in USDA hardiness zones 8b through 10; and 'True Green' has glossy, deep green leaves, a graceful, round-headed outline, and tends to be evergreen.
Propagation is by cuttings or grafts.
Pests
Borers and chewing insects may infest elm. Shows considerable resistance to elm leaf beetle and Japanese beetle.
Diseases
It is usually resistant to Dutch elm disease and phloem necrosis. Cankers may develop on young trunks where soil is excessively wet. These occur on nursery and landscape trees. The causal agent has not been identified but theories abound. Twig blight can be an occasional problem.
