Eastern cottonwood | The Morton Arboretum

Family (English) Willow
Family (botanic) Salicaceae
Planting site Residential and parks
Tree or plant type Tree
Foliage Deciduous (seasonally loses leaves)
Native locale Chicago area, Illinois, North America
Size range Large tree (more than 40 feet)
Mature height 75-100 feet
Mature width 50-75 feet
Light exposure Full sun (6 hrs direct light daily)
Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
Soil preference Moist, well-drained soil, Wet soil
Tolerances Alkaline soil, clay soil, Dry sites, Occasional drought, Occasional flooding, Wet sites
Season of interest early fall
Flower color and fragrance Inconspicuous
Shape or form Irregular, Pyramidal, Round
Growth rate Fast
Transplants well Yes
Planting considerations Highly susceptible to ice damage, Roots prone to invading sewer pipes, Weak wood and branch structure
Wildlife Mammals, Sapsuckers, Songbirds
Has cultivars Yes

More Information

Native Geographic Location and Habitat

C-Value: 2. This tree is native to eastern North America through the Midwest and the Chicago Region. It can be found growing along streams, rivers, and lowland areas.

Bark Color and Texture

Mature trees produce an ash-gray, blocky, thick bark with deep furrows and ridges.

Leaf Arrangement, Size, Shape, and Texture

This tree has an alternate leaf arrangement with 2 to 5 inch long, simple, triangle-shaped, deciduous leaves. These leaves have a toothed margin and an elongated tip. The leaf petiole is 3 to 4 inches long and flattened. Leaf buds are large, 1 inch long, reddish-green and pointed. Leaves are green in summer, turning yellow or brown in fall.

Flower Arrangement, Shape, and Size

Eastern cottonwoods are dioecious. Male trees have dangling reddish catkins before leaves appear. Female trees have yellow flowers.

Fruit, Nut, and Seed Descriptions

Fruit of the Eastern cottonwood is a dangling cluster of dehiscent capsules in May and June (on female trees only). Each seed produces a bit of fluff to aid in wind dispersal.

Care Knowledge

Plant Care

Eastern cottonwoods transplant easily, prefer wet soils in full sun, and is adaptable to various soil pH. It is drought tolerant. It is extremely fast growing which makes it weak-wooded and brittle. The tree produces suckers and aggressive roots.

Pests, Diseases and Tolerances

Roots are shallow and can invade septic and sewer systems. The female trees can be messy, producing large quantities of seeds with white ‘fluff’ attached. It is susceptible to a wide range of diseases including dieback, cankers, leaf spots, rusts and powdery mildew. Problem insects include borers, aphids, caterpillars and scale.