Eastern cottonwood (Populus deltoides): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Populus deltoides Bartr. ex Marsh., willow family
Other names	Southern cottonwood, Carolina poplar, eastern poplar, necklace poplar and alamo (Silvics); the Wood Handbook adds whitewood
Varieties, Silvics	Eastern cottonwood (var. deltoides) and plains cottonwood (var. occidentalis)
Native status, USDA PLANTS	Native in Canada and in the lower 48 states
Record size, Silvics	Heights of 53 to 58 m (175 to 190 ft) and diameters of 120 to 180 cm (48 to 72 in) reported
Green weight of the wood, NRS-38	50 lb per cubic foot, without bark

Native range

The Silvics of North America handbook (Agriculture Handbook 654, 1990) says eastern cottonwood grows along streams and on bottom lands from southern Quebec westward into North Dakota and southwestern Manitoba, south to central Texas, and east to northwestern Florida and Georgia. It is absent from the higher Appalachian areas and much of Florida and the Gulf Coast except along rivers. The handbook says the western boundary is not well defined, because the eastern variety intergrades with the plains cottonwood where the ranges overlap. It calls the tree one of the largest eastern hardwoods and the fastest-growing commercial forest species in North America, though short-lived, growing best on moist well-drained sands or silts near streams.

Size and growth

Silvics calls eastern cottonwood one of the tallest species east of the Rocky Mountains, and gives the record sizes in the table above. It reports age 35 stand volumes exceeding 420.0 cubic meters per hectare (30,000 board feet per acre) of sawed lumber. The most rapid growth recorded was on trees planted on favorable sites in the South with adequate weed control: heights of 13 m (43 ft) at age 3 and more than 30 m (100 ft) at age 9 on individual trees.

Flowers

The handbook says eastern cottonwood is dioecious, with a sex ratio of about 1 to 1. Flowering occurs from February to April before leaves appear. Male flowers are 8 to 13 cm (3 to 5 in) long, reddish and more conspicuous than the female flowers, which elongate to 15 to 30 cm (6 to 12 in). Trees as young as 4 to 5 years old have flowered. Seeds develop 30 to 60 per capsule on long catkins, and each capsule has 3 or 4 valves. On planting, the handbook says male clones, which have none of the objectionable "cotton" associated with seed, are preferred where the tree is planted for quick shade near homes.

Roots

Silvics says root growth of new seedlings is so slow that the plants are easily dislodged by rain droplets, and that after the first 3 weeks it accelerates. Most of the roots are in the uppermost, best aerated layer of soil, nearer the surface in clay soils than in loam soils. After siltation, roots develop on the covered portion of the stem. It adds that trees planted from conventional cuttings of 20 to 60 cm (8 to 24 in) have fewer deep roots and are not as well anchored against root lodging as those established naturally or as deep-planted seedlings or rooted cuttings.

Wood

The Wood Handbook (FPL-GTR-282, 2021) says the heartwood of cottonwood is grayish white to light brown. Eastern cottonwood is moderately low in bending and compressive strength, moderately stiff, moderately soft and moderately low in ability to resist shock, with moderately high shrinkage. It says some cottonwood is difficult to work with tools because of a fuzzy surface, mainly the result of tension wood, and that the wood is used principally for lumber, veneer, pulpwood, excelsior and fuel. Silvics adds that the lightweight, rather soft wood is used primarily for core stock in furniture manufacturing and for pulpwood.

Wood Handbook figure	Green	At 12% moisture content
Specific gravity (Table 5-3b)	0.37	0.40
Modulus of rupture, lbf per square inch (Table 5-3b)	5,300	8,500
Side hardness, lbf (Table 5-3b)	340	430
Moisture content of green cottonwood, percent (Table 4-1)	162 heartwood, 146 sapwood	Not applicable

The green weight of the wood is in the NRS-38 table, the same figure used in the log weight calculator.

Pests and diseases the handbook names

Silvics (1990) says at least 10 insect species and 12 diseases cause major damage to eastern cottonwood across its range.

Borers. Two clearwing borers (Paranthrene dollii dollii on the lower stem and P. tabaniformis on terminals and small branches), the poplar borer in trunks of trees 3 or more years old, the cottonwood borer at the root collar and roots, and the cottonwood twig borer.
Leaf feeders. The cottonwood leaf beetle and the poplar tentmaker, which the handbook says can cause repeated defoliation resulting in mortality.
Cankers. Septoria musiva, which it says causes a small canker that opens a path for other canker organisms, Cytospora chrysosperma, Fusarium solani, Phomopsis macrospora and Botryodiplodia theobromae. It says that on vigorous trees cankers usually callus over.
Leaf diseases. Leaf rust from Melampsora medusae, and leaf spot from Marssonina brunnea and Septoria musiva.
Flood, fire and animals. The handbook says floods during the dormant season or of short duration in the growing season may benefit trees, that prolonged floods or stagnant water pools are harmful, and that cottonwood of all ages is very susceptible to fire. Rabbits, deer and domestic stock browse young trees, and beavers cut saplings and poles.

The guide on reporting a pest in the United States gives the office that takes sightings of regulated pests, and pests and diseases by country sets out which ones agencies regulate. Who may apply pesticides is in pesticide licences by country.