Aspen, Quaking or Trembling

Populus tremuloides

Salicaceae - Willow Family

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

General

Salicaceae - Willow
Family:
No
Cultivar Availability:
3 - 7
Hardiness Zone:
Broadleaf
Type:
Yes
Utah Native:

Growth

Medium
Growth Rate:
High
Mature Height:
Medium
Longevity:
No
Power Lines:
Oval
Crown Shape:

Ornamental

Yes
Bark:
Yes
Fall Color:
No
Flowers:
Yes
Foliage:
No
Fruit:

Tolerance of...

Low
Shade:
Medium
Salt:
Medium
Drought:
Medium
Poor Drainage:
Medium
Alkalinity:
High
Transplanting:
x

Family

A group of closely related species and genera; scientific name ends in 'aceae'.

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Cultivar Availability

Cultivar Availability means that selected, genetically pure trees are available with known characteristics. Cultivars often prove to be more desirable than trees grown from seed or collected in the wild.

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USDA Hardiness Zone

Pick a hardiness zone to show which trees are suitable.

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Tree Type

Select Conifer for pines, firs, junipers, ginkgo, and other conifers (gymnosperms). Select Broadleaf for trees with broad, flat leaves (more or less) (angiosperms).

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Utah Native

Utah Native

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Growth Rate

Growth rate refers to height growth for the first ten years after a tree is planted. Select Low for less than 12-inches/year height growth. Select Low-Medium for low or medium growth rate. Select Medium for 12- to 24-inches/year height growth. Select Medium-High for medium or high growth rate. Select High for more than 24-inches/year height growth.

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Mature Height

Mature height will vary considerably by cultivar and site and is shown here assuming adequate care. Select Low for less than 20 feet mature height. Select Low-Medium for low or medium mature height. Select Medium for 20 to 40 feet mature height. Select Medium-High for medium or high mature height. Select High for more than 40 feet mature height.

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Longevity

The typical life span of a good tree in a suburban neighborhood is 30 to 50 years, while downtown trees may only last 5 to 10 years. People tend to plant fast-growing trees that often have fairly short lives. While some of this is all right, homeowners and communities should also plant trees that might grow slower (though some grow quite fast) but that are longer-lived. Select Low for less than 25 years typical life span. Select Medium for 25 to 50 years typical life span. Select High for more than 50 years typical life span.

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Powerline Suitability

Only very short trees should be planted under or directly adjacent to overhead electric lines. Medium height trees should be offset 15 to 20 feet horizontally from electric lines. Large trees should be offset 30 feet. Wider crowned trees like elms or maples should be offset more than narrower crowned trees like spruces or firs. If you suspect that you are planting in an area with underground electric lines or other buried utilities, call Blue Stakes at 1-800-662-4111 to have utilities located and marked. 'Yes' in this database means a tree is suitable for planting directly under powerlines. 'No' means it is not.

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Crown Shapes

Crown shape varies considerably by cultivar and sometimes by site. The common crown shape for a species is shown as follows: Pyramidal, Round, Columnar, Weeping, Broad, Oval, Vase, Layered, Shrubby, and Irregular.

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Ornamental Features

Ornamental characteristics are important factors in tree selection even though they usually have little to do with whether a tree can survive and thrive on its site. Ornamental factors to consider include flower and fruit presence and appearance, foliage color and texture, bark characteristics, shade density, fall color, and winter appearance. Some trees have thorns or spines, objectionable odors, a tendency to have basal or root sprouts, or maintenance-related needs that also should be considered. 'Yes' in this database means that a species is noted for a particular ornamental feature; 'No' means it is not, though there may be exceptions depending on cultivar.

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Tolerance of Shade

Shade tolerant plants often are best planted in at least partial shade, though many will do well in full sun. Shade intolerant plants usually need full sun to thrive.

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Tolerance of Salt

Generally means tolerance to salt on above ground plant surfaces, though may indicate some tolerance to soil salinity.

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Tolerance of Drought

Indicates the tree's tolerance of low soil moisture, heat and/or low humidity.

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Tolerance of Poor Drainage

Indicates the tree's tolerance to waterlogging, compaction, or otherwise poorly oxygenated soil.

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Tolerance of Alkalinity

Indicates the tree's tolerance of high soil pH or soil alkalinity; soil pH above 6.5 or 7.

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Ease of Transplanting

This describes a tree's relative likelihood of transplanting success. A low ranking indicates a plant that may need extra care at planting and may do better if transplanted while fairly small. Select Low for low transplanting difficulty. Select Medium for medium transplanting difficulty. Select High for high transplanting difficulty.

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Add Trees to Favorites

The button to the right of the tree name allows you to add the tree as a favorite (stored as a browser cookie). For example, if the "Alder, European or Common" is one of your favorite trees click or touch the button to the right of the tree name and it will be added to your favorites. You will then be able to view your favorites as long as you are on the same device.