Chinese Elm
Ulmus parvifolia ‘Drake’
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 fastgrowing, 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.
GENERAL INFORMATION
Scientific name: Ulmus parvifolia ‘Drake’
Pronunciation: UL-mus par-vih-FOLE-ee-uh
Common name(s): ‘Drake’ Chinese Elm, ‘Drake’
Lacebark Elm
Family: Ulmaceae
USDA hardiness zones: 7B through 10
Origin: not native to North America Uses: large parking lot islands
(> 200 square feet in size); wide tree lawns (>6 feet wide);
medium-sized parking lot islands (100-200 square feet in size); medium-sized
tree lawns (4-6 feet wide); recommended for buffer strips around
parking lots or for median strip plantings in the highway; reclamation
plant; shade tree; small parking lot islands (< 100 square feet
in size); narrow tree lawns (3-4 feet wide); specimen; sidewalk cutout
(tree pit); residential street tree; tree has been successfully grown
in urban areas where air pollution, poor drainage, compacted soil,
and/or drought are common
Availability: generally available in many areas within its hardiness
range
DESCRIPTION
Height: 35 to 45 feet
Spread: 35 to 50 feet
Crown uniformity: symmetrical canopy with a regular (or smooth) outline,
and individuals have more or less identical crown forms
Crown shape: round; spreading; vase shape; weeping
Crown density: moderate
Growth rate: medium
Texture: fine
Foliage
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: serrate; serrulate
Leaf shape: elliptic (oval); obovate; ovate
Leaf venation: pinnate
Leaf type and persistence: evergreen; semievergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: yellow
Fall characteristic: not showy
Flower
Flower color: green
Flower characteristics: fall flowering; inconspicuous and not showy
Fruit
Fruit shape: oval
Fruit length: < .5 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; inconspicuous and
not showy; no significant litter problem
Trunk and Branches
Trunk/bark/branches: bark is thin and easily damaged from mechanical
impact; droop as the tree grows, and will require pruning for vehicular
or pedestrian clearance beneath the canopy; routinely grown with,
or trainable to be grown with, multiple trunks; showy trunk; tree
wants to grow with several trunks but can be trained to grow with
a single trunk; no thorns
Pruning requirement: requires pruning to develop strong structure
Breakage: resistant
Current year twig color: brown; gray
Current year twig thickness: thin
Culture
Light requirement: tree grows in part shade/part sun; tree grows
in full sun
Soil tolerances: clay; loam; sand; acidic; occasionally wet; alkaline;
well-drained
Drought tolerance: high
Aerosol salt tolerance: moderate
Other
Roots: surface roots are usually not a problem
Winter interest: tree has winter interest due to unusual form, nice
persistent fruits, showy winter trunk, or winter flowers
Outstanding tree: tree has outstanding ornamental features and could
be planted more
Invasive potential: little, if any, potential at this time Verticillium
wilt susceptibility: susceptible
Pest resistance: long-term health usually not affected by pests
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 mid-west. 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, wellestablished 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), whitemargined 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.
by Edward F. Gilman and Dennis G. Watson
