Chinese Elm (Ulmus parvifolia)

Chinese Elm, Drake Elm, Lacebark Elm

Chinese elm (Ulmus parvifolia) is a small, deciduous elm tree native to China, Japan, North Korea, and Vietnam. This tree is considered to have the hardest wood of all elm tree species. Commercially, its wood is used to make baseball bats, bows, and the handles of tools. Ornamentally, the chinese elm is used in landscaping in areas with a good amount of full sunlight.

I. Appearance and Characteristics 

Ulmus parvifolia, commonly known as the Chinese elm or lacebark elm, is a species native to eastern Asia, including China, India, Japan, Korea, and Vietnam. It has been described as “one of the most splendid elms, having the poise of a graceful Nothofagus”.

The tree was introduced to the UK in 1794 by James Main, who collected it in China for Gilbert Slater of Low Layton, Essex.

A small to medium deciduous or semi deciduous (rarely semi evergreen) tree, it grows to 10–18 m (33–59 ft) tall and 15–20 m (49–66 ft) wide with a slender trunk and crown. The leathery, lustrous green, single-toothed leaves are small, 2–5 cm long by 1–3 cm broad, and often retained as late as December or even January in Europe and North America. The apetalous wind-pollinated perfect flowers are produced in early autumn, small and inconspicuous. The fruit is a samara, elliptic to ovate-elliptical, 10–13 mm long by 6–8 mm broad. The samara is mostly glabrous, the seed at the center or toward the apex, is borne on a stalk 1–3 mm in length; it matures rapidly and disperses by late autumn. The trunk has a handsome, flaking bark of mottled grays with tans and reds, giving rise to its other common name, the lacebark elm, although scarring from major branch loss can lead to large, canker-like wounds.

Many nurserymen and foresters mistakenly refer to Ulmus pumila, the rapidly growing, disease-ridden, relatively short-lived, weak-wooded Siberian elm, as “Chinese elm”. This has given the true Chinese elm an undeserved bad reputation. The two elms are very distinct and different species. The Siberian elm’s bark becomes deeply ridged and furrowed with age, among other obvious differences. It possesses a very rough, grayish-black appearance, while the Chinese elm’s smooth bark becomes flaky and blotchy, exposing very distinctive, light-coloured mottling, hence the synonym lacebark elm for the real Chinese elm.

II. How to Grow and Care

Growing and caring for a lacebark elm in your landscape is an easy endeavor, especially if you are in an area that does not experience cold or harsh winters or high winds.

The only ongoing maintenance that the species requires is some structural pruning to avoid breakage due to weather.

Sunlight

For vigorous growth, full sun is preferred. If the tree does not receive enough light, it will grow slowly with slender branches that have a longer leaf spacing and a lighter leaf color. Summer is the most active growth season for chinese elm, making adequate sunlight essential at this time.

Temperature and Humidity

The lacebark elm is tolerant of a good range of temperatures that cover much of the United States. It thrives in USDA zones 5-9.

It does have issues withstanding ice buildup and high winds, which needs to be considered when placing the tree in a landscape and determining its usage.

Watering

When initially planted, the lacebark elm needs to be watered weekly to ensure the roots establish themselves. It is important to remember that less frequent, deeper watering is preferable to frequent, light irrigation.

Once the tree is established, there is no real need to continue with supplemental watering. The species has a good tolerance for droughts.

Soil

Chinese elm can tolerate a variety of different soil types and pH values, but good drainage is a must. Fertile sandy loam is best suited to the tree’s growth, and this can be mixed with garden soil, leaf mold and river sand at a ratio of 1:1:1 as cultivation soil.

Fertilizing

During the growth period of Chinese elm in the warmer seasons, a diluted organic water-soluble fertilizer can be applied once a month. Fertilizing should be stopped after the plant goes into hibernation in the winter, but an organic fertilizer can be applied to the soil under the projection of the outer edge of the tree crown just before spring.

Planting Instructions

Seeds mature in the spring, with robust plants that are between 15 to 30 years old being best for harvesting seeds from. Air-dry the seeds, and then remove shells and impurities before sowing. It is best to sow the seeds directly after harvesting them, otherwise they will need to be stored in a well-sealed environment.

Place seedlings into fertile sandy loam with good drainage, and irrigate. Once the seedlings grow 2-3 leaflets, any weak seedlings should be removed, leaving 15 seedlings along a 1 m stretch of soil. In the seedling stage, scarification and weeding should be carried out regularly, and soil should be kept moist. The most vigorous growth period for seedlings is early summer, which is when plants should be topdressed every fortnight. The height of a 1-year-old seedling can reach more than 1 m, so ensure that you have adequate space.

Pruning

Perform proper preliminary maintenance to protect a lacebark elm during storms and winter months. When planting, stake the tree to encourage upright growth.

Train the tree with structural pruning to establish a single leader. Prune to eliminate any deep V-shaped intersections and inner-pointing interior branches. 

Maintaining this schedule annually for the first few years will keep the tree structurally sound for some time into the future.

Propagation

The lacebark elm is easy to transplant and can be propagated, particularly for use in bonsai. You will need sharp scissors that have been sterilized. Propagation can be done in the late spring and early summer. Here’s how to propagate lacebark elm through cuttings:1

  • Select a branch from a healthy tree containing mature foliage.
  • Taking your scissors, cut the branch off. Proceed to take cuttings 2-4″ long and 1/8″ thick below the leaf nodes.
  • Remove the leaves from the bottom two-thirds of the cuttings.
  • Place the cuttings in water and prepare pots with moist peat moss (you can mix in perlite or vermiculite). Using a pencil or your finger, make a hole in the center of the soil.
  • Dip the cut ends in rooting hormone and place cuttings in pots. Firm the soil around the stems. Water regularly.
  • Keep pots in a warm place for 8-10 weeks until the cuttings take root.

Pests and Diseases

Common Pests & Plant Diseases

If you see leaves wilting and/or yellowing, particularly during the summer months, it could be a condition called elm yellows. While most lacebark elms are resistant to this disease, they can occasionally contract it. There is no way to control the disease and you will need to remove the tree and stump to prevent it spreading to other trees.

Common Problems 

Fortunately, lacebark elm is relatively easy to grow and doesn’t experience many problems. Anything that comes up tends to be very minor. That said, here are a few things to look out for.

Cankers

You may notice cankers forming on twigs and branches. Leaves can then turn yellow and fall. To treat, prune the infected branches below the canker and disinfect the tools afterward.

Rotting Bark

Overwatering can cause the bark to rot. Scale back on watering and make sure not to drown your plant. Soil should be well-drained and not overly moist.

Overwintering

While this tree is hardy in the ground within its hardiness range, a potted specimen could die outdoors if temperatures reach freezing. Move indoors and place by a well-lit window or on a covered porch. You want to avoid allowing it to get too cold in the winter, though going dormant is normal.

III. Uses and Benefits 

  • Ornamental uses

A towering, stately addition to almost any landscape, the chinese elm offers gardeners a great shade or specimen tree in winter gardens. It is prized for its ornamental value, with its mottled bark of cream, brown, green, and orange tones and great foliage. It can be accompanied by groundcovers such as hosta and daffodil or trees such as eastern redbud and Green Giant thuja.

  • Other uses

Elms, hickory, and ash all have remarkably hard, tough wood, making them popular for tool handles, bows, and baseball bats. Chinese elm is considered the hardest of the elms. Chinese elm is said to be the best of all woods for chisel handles and similar uses due to its superior hardness, toughness, and resistance to splitting. Chinese elm lumber is used most for furniture, cabinets, veneer, hardwood flooring, and specialty uses such as longbow construction and tool handles. Most commercially milled lumber goes directly to manufacturers rather than to retail lumber outlets.

Chinese elm heartwood ranges in tone from reddish-brown to light tan, while the sapwood approaches off-white. The grain is often handsome and dramatic. Unlike other elms, the freshly cut Chinese elm has a peppery or spicy odor. While it turns easily and will take a nice polish off the lathe without any finish, and it holds detail well, the fibrous wood is usually considered too tough for carving or hand tools. Chinese elm contains silica which is hard on planer knives and chainsaws, but it sands fairly easily. Like other woods with interlocking grain, planes should be kept extra sharp to prevent tearing at the grain margins. It steam-bends easily and holds screws well, but pilot holes and countersinking are needed. It tends to be a “lively” wood, tending to warp and distort while drying. This water-resistant wood easily takes most finishes and stains.

Chinese Elm (Ulmus parvifolia) Details

Common name Chinese Elm, Drake Elm, Lacebark Elm
Botanical name Ulmus parvifolia
Plant type Perennial
Hardiness zone 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a
Growth rate Medium
Harvest time Fall
Height 40 ft. 0 in. - 50 ft. 0 in.
Width 40 ft. 0 in. - 50 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Green
Leaf color Green