Ulmus pumila aka Siberian Elm

Ulmus pumila, or Siberian elm, belongs to the elm family. This deciduous tree comes from eastern Siberia and northern China. Its native range also includes Manchuria and Korea. People brought it to the United States in the 1860s. It now grows across much of the country. It spreads beyond gardens and forms thick stands in some states. Connecticut records it as a tree with invasive traits.

It grows fast and forms an upright, vase-shaped crown. The crown can become open and uneven with age. Garden trees reach 50–70 feet [15.2–21.3 metres] tall. North Carolina State gives widths of 35–50 feet [10.7–15.2 metres]. UConn reports trees as wide as their height. RHS notes that height can reach 98 feet [30 metres]. Many thin branches hang down from the crown. Mature bark is gray, with grooves and ridges. The slender, gray twigs bend in a zigzag pattern.

The simple leaves grow in an alternate pattern along stems. Their blades are oval to narrow, with toothed edges. The two sides of the leaf base can differ. Leaves have dark green tops and paler lower surfaces. Fall brings yellow or yellow-brown leaves, with little display value. Small green to red flowers open before the leaves. They grow in loose clusters from March to May. Each flower has both sex organs and can self-pollinate. The fruit is a round, winged samara with one seed. Green fruit dries brown, and wind carries it away.

Plant it in full sun and soil that drains well. RHS also allows partial shade and moist, well-drained soil. It accepts clay, loam, sand, and poor soil. It tolerates drought and a broad range of soil pH. Sources place it in USDA zones 4–9 and UK H6. People use it for windbreaks, rural hedges, and slope erosion control. Its weak limbs make it a poor choice for ornamental planting. Wind, ice, and snow can break branches, creating frequent cleanup. Seeds and suckers help it spread and hinder removal.

Elm leaf beetles, aphids, borers, and scale can attack it. Disease problems include mildew, leaf spot, cankers, wilts, and rots. It resists Dutch elm disease but is not immune. PFAF lists leaves and young fruit as edible, raw or cooked. Cooked inner bark can supply flour or a soup thickener. That source reports no known hazards, rather than proven safety. It also records bark fibre, timber uses, and traditional medicinal uses.