Quaking Aspen
Populus tremuloides (SALICACEAE)
Planting and Growing Quaking Aspen Trees
You’ll find everything you need to know to plant and grow quaking aspen trees in the accompanying table’s tabs:
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- Foliage, catkins, and seeds of quaking aspen
- Growing conditions for quaking aspen
- When to plant quaking aspen
- How to plant quaking aspen
- How to prune quaking aspen
- Watering, fertilizing, and care of quaking aspen
- Landscape uses of quaking aspen
- Pest and disease control for quaking aspen
Growing Quaking Aspen Trees
Several cultivars of fast-growing, short-lived, upright, branching, open, deciduous trees, to 60 ft. (18 m) tall and 30 ft. (9 m) wide, with shiny, light green, heart-shaped, pointed, toothed leaves, 1–3 in. (25–75 mm) long, turning gold, yellow in autumn, and with gray green, white, smooth becoming rough bark.
Aspen and poplar trees are both members of the Populus genus.
Quaking Aspen Planting and Care Guide
Catkins and Seeds
Willowlike catkins, to 1 in. (25 mm) long, in early spring before leaves emerge, form brown, clustered, hairy seed, 1/2–1 in. (12–25 mm) long, in spring.
Best Climates
U.S.D.A. Plant Hardiness Zones 2–8. Hardy. Best in cold-winter climates, high elevations.
Soil Type and Fertility
Moist, well-drained soil. Fertility: Rich–average. 5.5–7.0 pH.
Where and How to Plant
Full sun. Space 8–12 ft. (2.4–3.7 m) apart.
Proper Care
Moderate. Keep evenly moist. Avoid fertilizing. Prune in autumn to shape, remove suckers. Propagate by cuttings, grafting, seed, suckers.
About This Species
Good choice for borders, fencelines, groups, screens in cold-climate, mountain, woodland gardens. Drops leaves, seed, twigs, requiring maintenance. Very invasive. Shallow rooted. Generally disease resistant. Cottonwood leaf beetle, poplar curculio, scale susceptible.
Common Species and Varieties of Poplar
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- Populus X acuminata, lance-leaved cottonwood
- Populus alba, white poplar
- Populus angustifolia, narrow-leaved poplar
- Populus balsamafera, balsam poplar
- Populus X berolinensis, Berlin poplar
- Populus X canadensis, Carolina poplar
- Populus canescens, big-leaved poplar
- Populus deltoides, eastern poplar
- Populus fremontii, western cottonwood
- Populus grandidentata, large-toothed aspen
- Populus lasiocarpa, Chinese poplar
- Populus maximowiczii, Japanese poplar
- Populus nigra ‘Italica’, Lombardy poplar
- Populus simonii, Simon poplar
- Populus tremuloides, quaking aspen
- Populus trichocarpa, black cottonwood
About Poplar Trees
The Populus genus includes between 30 and 40 species of erect, slim, broad-leaved, deciduous trees, from as small as 15–20 ft. (4.5–6 m) tall and to as large as 100 ft. (30 m). They are native to the northern hemisphere. All are hardy and grow best in cold-winter, mild-summer areas that experience winter chill below 20°F (–7°C) for several months.
Poplars are prized for their narrow or round-crowned form and their graceful foliage, which colors to gold, red, and yellow in autumn. Because they are fast-growing and short-lived, their best use is as a temporary filler or accent.
Keep in mind that aspen and poplar are shallow-rooted trees that tend to be invasive.
While they are moderately pest and disease resistant while young, they quickly become susceptible to beetle, poplar curculio, and scale as they mature and their growth slows. Also plan for frequent rakings to remove their fallen catkins, leaves, seed, and twigs.
Aspens, cottonwoods, and poplars are often featured in landscapes found in cold-winter climates, along creeks and rivers, or where soils are naturally moist.
Because poplar species are so varied, consider choices beyond the ones listed at left. Consult your garden retailer’s staff for advice on the best poplar species to plant in your region.Choose from among the popularly cultivated species above, at left.
Planting and Caring for Poplars
Poplars, aspens and cottonwoods are broad-leaved and deciduous, with attractive, heart-shaped leaves and open crowns. Because their wood is weak and branches sometimes fail at the crotch, they should be planted away from structures.
Plant poplars in moderately rich, moist, well-drained, acidic soil. All landscape trees grow best if planted in unamended soil; test the acid-alkaline balance of your site before you plant. Poplars should have soils in the 5.5–7.0 pH range. Choose those species that fit your climate and site.
When planting poplars, carefully match the depth of the planting hole to the soil line on the rootball of your tree. They do best when planted with their roots at the same depth below ground as they were grown at the nursery.
Backfill around the rootball with native soil and give the tree ample water, keeping the soil evenly moist until the tree becomes established. Avoid applying fertilizer as you plant poplars.
Care needs for poplars include regular raking of fallen catkinlike flowers, leaves, twigs, and winged seed.
Large poplars are good for seasonal shade above mixed-shrub borders, while those with smaller, more delicate forms are good landscape accents. In small-space gardens, the smaller species also make good container plants for use on balconies, decks, and patios. Be sure to regularly water all container trees.