At a Glance
TypeTree
HabitSpreading
FoliageSemi-evergreen
Height40-50 feet (12-15 m)
Width25-40 feet (7.5-12 m)
Maturity25 years
Overview
Ulmus parvifolia is a deciduous to semi-evergreen elm reaching 40-50 feet (12-15 m) tall and 25-40 feet (7.5-12 m) wide at maturity, with a rounded to vase-shaped crown. Native to East Asia and introduced to North American landscapes in the late 1700s. Mature bark exfoliates in irregular plates revealing a mottled mosaic of cream, gray, green, and orange-brown tones. Leaves alternate, 0.7-2 inches (2-5 cm) long, ovate to elliptic with single or shallow doubly serrate margins; emerge medium green and remain dark green through summer, turning yellow to red-purple in fall. In zones 8-10 some leaves persist through mild winters. Small green-white flowers in clusters open in late August through September, after the spring bloom of most other elms. Flat samaras 0.3 inch (8 mm) across mature in November. Growth rate 2-3 feet (60-90 cm) per year. Resistant to Dutch elm disease in inoculation trials and to elm leaf beetle defoliation. Tolerates compacted urban soils, road salt, and seasonal drought once established.
Native Range
Ulmus parvifolia is native to East Asia, occurring in central and eastern China, Korea, Japan, Vietnam, and Taiwan. The species inhabits riverbanks, woodland margins, and rocky slopes at elevations from sea level to 5,000 feet (1,500 m). Introduced to North America in the late 1700s and now widely cultivated as a landscape tree.Suggested Uses
Commonly planted as a street tree in zones 5-9 with 25-35 foot (7.5-11 m) spacing for canopy coverage. Used as a shade tree in residential lawns; mottled exfoliating bark stays visible from fall through spring after leaf drop. Tolerates urban compacted soils, road salt, summer heat, and seasonal drought; performance in zones 4-5 is reduced due to occasional twig dieback in late spring frost.How to Identify
Appearance
Size & Dimensions
Height40' - 50'
Width/Spread25' - 40'
Reaches mature size in approximately 25 years
Bloom Information
Small green-white clusters of bisexual flowers open in late August through September, after the spring bloom of most other elm species. Flat green samaras 0.3 inch (8 mm) across develop within 6-8 weeks of pollination and mature to papery tan in November. Wind disperses samaras up to 300 feet (90 m) from the parent tree. Bloom timing varies by latitude, with peak release 2-3 weeks earlier in zones 8-9 than in zones 5-6.Detailed Descriptions
Foliage Description
medium to dark green in summer; turns yellow to red-purple in fallGrowing Conditions
Sun Requirements
Requires 4-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Newly planted trees require 10-15 gallons (38-57 L) of water per week during the first growing season, decreasing to bi-weekly watering during the second season. Mature trees tolerate 6-8 weeks of summer drought and continue active growth in soil temperatures up to 95°F (35°C). A 2-3 inch (5-8 cm) layer of organic mulch in a 4-foot (1.2 m) radius around the trunk reduces lawn competition and conserves moisture. Annual fertilization is unnecessary on most soils; chlorosis is rare and develops only on alkaline sites with low organic matter. Resistant to Dutch elm disease in inoculation trials and to elm leaf beetle defoliation. Twig dieback can occur after late spring frost events in zones 4-5 but is followed by complete recovery within one growing season.Pruning
Structural pruning is performed in winter from December through February while the tree is dormant. Removal of co-dominant leaders before the tree reaches 6 inches (15 cm) of trunk diameter prevents future bark inclusions. Cuts up to 4 inches (10 cm) callus over within 2-3 growing seasons. Branchlet pruning in summer maintains a more open crown and increases bark exposure on the lower trunk.Pruning Schedule
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