Aspen, Quaking or Trembling
Populus tremuloides
Salicaceae - Willow

Description

Leaves: Simple; alternate; round to broadly ovate; 1-1/2" to 3" diameter; deciduous; finely serrate margin; acute apex; glabrous; yellow-green to green, turning bright yellow to orange in fall; petiole 1-1/2" to 3" long, flattened laterally, causing leaf to flutter in the wind.

Twigs/buds: Twigs slender; glabrous; red-brown. Terminal bud 1/4" to 1/2" long, sharp-pointed, sometimes resinous, covered by red-brown overlapping scales; lateral buds smaller, curve inward.

Flowers/fruit: Primarily dioecious; fruit a capsule; narrow conical; 1/4" long; gray and hairy; seeds small, tufted, light brown.

Bark: Smooth; green-white to cream colored; becomes furrowed on older trunks.

Wood: Important; heartwood gray-white to light gray-brown; sapwood lighter and merges gradually into heartwood; straight grained; fine textured; growth rings unclear; diffuse-porous; used for lumber, pallets, crates, pulp, and matches.

General: Utah's official state tree. Native in most of the northern and western U.S. and Canada, including higher elevations in Utah. Generally forms single aged stands through root sprouts after a fire or other disturbance; grows in clumps or "clones" that are genetically identical since stems are all attached to the same root system. Relatively short-lived. Grows in cool, moist areas. Very shade intolerant.

Landscape Use: Over-planted in Utah; also found where homes are built into native aspen areas. Native trees do well, but aspen does not like the heat and dry conditions in our lower valleys. Stressed aspens suffer from leaf scorch, leaf spot, borers, cankers, galls, occasionally iron chlorosis, and many other problems. Best grown in cooler high-mountain climates that it is used to. If grown at low elevations, avoid problems with older, larger trees by managing selected aspen sprouts in a large, mulched bed; remove stems before they get very large. Zones 3-7.

Comments & Limitations: May be insect and/or disease prone, especially when stressed. Sucker (sprout) growth can be a problem. Rarely should be planted, though limited use in specific situations may be justified.

Cultivars: 'Driefest', 'Erecta', 'Mountain Sentinel', 'Pendula', 'Prairie Gold'.

Characteristics

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