Larry, Joe, Erik,
Thanks, Guys. Joe, I've not forgotten your suggestion to write an article on what our kind of measurement data is important. I think a brainstorming session where everyone has a chance to list their reasons would be the right starting point. I'd bet we could come up with some pretty original reasons.
In communicating with VA Tech's Dendrology people, I gave them a copy of my black birch database, which presently contains 671 measurements spread across 12 states. This database makes the point abundantly clear that traditional sources under-describe the maximum growth attained by this species, and some by a lot.
VA Tech takes most of their descriptions from a USDA plant database, USFS Silvics of North America, and at least one other source - all ostensibly credible. Here's what these and other sources say about the eastern cottonwood.
USDA Plant Database
Populus deltoides Bartr. ex Marsh., eastern cottonwood, is a fast-growing tree which reaches 80 to l00 feet in height and 3 to 4 feet in diameter. It is a relatively short-lived tree, seldom surviving for more than 80 years.
GENERAL BOTANICAL CHARACTERISTICS:
Eastern cottonwood is a native, deciduous bottomland hardwood [68,121,132,212,225]. Height ranges from 36 to 190 feet (11-57.9 m) [37,47,56,67,120,132,150,151,224]. At maturity (approximately 35 years) , diameter at breast height ranges from 10.7 inches to more than 6 feet (27.2-182.9 cm) [7,47,67,132,150,224]. In open areas, eastern cottonwood typically has a large trunk that divides into branches near its base and ascends to form a wide, spreading crown [47,100]. In closed stands, it tends to have a tall, straight, and relatively branch-free bole with a small rounded crown . Life expectancy is approximately 100 to 200 years [9,120,142]. It is dioecious. Female catkins range from 2 to 5.1 inches (5-13 cm) long, and fruit capsules are 0.3 to 0.6 inch (.8-1.5 cm) long . The bark is thick and deeply furrowed with wide, flat ridges [56,199]. The rooting depth averages 100 inches (254 cm) , and mature stands can reach 117.6 to 196.8 inches (298.7-499.9 cm) rooting depth .
Missouri Botanical Garden
common Name: eastern cottonwood
Native Range: Eastern and central United States
Zone: 2 to 9
Height: 50.00 to 80.00 feet
Spread: 35.00 to 60.00 feet
Bloom Time: March to April
Bloom Description: Red (male) and green (female)
Sun: Full sun
Water: Medium to wet
Suggested Use: Shade Tree, Rain Garden
Tolerate: Drought, Air Pollution
USFS Silvics of North America
Growth and Yield- Eastern cottonwood is one of the tallest species east of the Rocky Mountains. Heights of 53 to 58 in (175 to 190 ft) and diameters of 120 to 180 cm (48 to 72 in) have been reported (17), as have age 35 stand volumes exceeding 420.0 m³/ha (30,000 fbm/acre) of sawed lumber (5,10,14,22).
Populus deltoides is a large tree growing to 20–40 m (65–130 ft) tall and with a trunk up to 1.8 m (5 ft 11 in) diameter, one of the largest North American hardwood trees.
Our NTS measurements confirm heights for the eastern cottonwood into the mid-150s. Most of the tall ones are in the 130s with a few in the 140s.
Robert T. Leverett
Co-founder and Executive Director
Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest