Populus angustifolia
Fast-growing, dioecious deciduous riparian tree native to western North America that establishes on alluvial bars, tolerates frequent flooding, regenerates rapidly from seeds and vegetative sprouts, and bears separate male and female catkins that open before leaves to produce cottony, wind-dispersed seeds, thereby stabilizing streambanks.
Common Names
Narrowleaf Cottonwood, Mountain Cottonwood
Summary
Narrowleaf cottonwood is a dioecious, fast-growing deciduous tree native to western North America from Alberta to Mexico, commonly found along streambanks in mountains, foothills, and dry plains. It reaches about 50–60 ft tall with a narrow, upright crown and has lanceolate to narrowly ovate leaves 2–5 in long with finely serrate margins; bark is smooth and light on young trees, aging to furrowed; catkins appear in early spring, and wind-dispersed fruits bear cottony seeds.
Growth requirements include full sun and moist, well-drained soils; tolerance of frequent flooding but not drought resistance; high water needs and riparian specialization; used for erosion control and wildlife habitat; wood historically used for fence posts and fuel; however, extensive root systems can invade drainage and damage foundations; plant away from structures, at least 12 m on clay soils. Propagation is by seed and cuttings; seeds and suckers are used in restoration; easily establishes on moist sites along streams.
Lifecycle
Perennial
Height
50-66 feet
Spread
20-30 feet
Hardiness Zones
Zones 3-7
Sunlight Requirements
Ideally full sun. Tolerates partial sun.
Soil Type
Deep, rich, well-drained circumneutral soil, loamy sand to sandy loam with high coarse-fragment content.
Soil Drainage
Moist, well-drained soils
Soil pH
6.0–7.5, circumneutral around pH 7, mildly acidic to mildly alkaline, broad pH tolerance
Bloom Color
White
Bloom Time
Spring
Foliage Color
Dark green upper surface with a whitish-green lower surface.
Fall Foliage Color
Yellow to orange
Leaf Lifecycle
Deciduous
Growth Rate
3–5 ft/year
Seasons of Interest
Spring and Summer
Propagation Methods
Seeds, Cuttings, Suckers (root suckers and adventitious sprouts from roots and root crown/branches), Root cuttings (root segments), Branch/root fragments sprouting, Vegetative/Clonal propagation
Attracts Wildlife
Attracts bees, Attracts butterflies, Attracts other pollinators, Attracts birds
Taxonomy
- Taxonomic Rank
- Species
- Author
- E.James
- Publication
- Account Exped. Pittsburgh 1: 497 (1823 publ. 1822)
Superior Taxa
- Kingdom
- Plantae
- Subkingdom
- Pteridobiotina
- Phylum
- Angiosperms
- Order
- Malpighiales
- Family
- Salicaceae
- Genus
- Populus
Synonyms
Populus tweedyi Populus balsamifera var. angustifolia Populus sennii Populus canadensis var. angustifolia Populus fortissima Populus coloradensis