Populus deltoides--Eastern Cottonwood Hardiness Zones: 3 to 9 Height: 85 ft Spread: 60 ft Form: rounded Type: deciduous tree Annual Growth Rate: more than 18 inches
Comments: Eastern Cottonwood grows rapidly but usually creates litter problems. Female trees produce copious amounts of white "cotton" after flowering. Poplars are problem-prone plants that require more care than other trees.
Cultivars: 'Siouxland' - A male cultivar that produces no "cotton" and attains a rounded form. Introduced by the South Dakota Plant Pathology Department.
Populus x canadensis--Carolina Poplar
Hardiness Zones: 2 to 6 Height: 50 ft Spread: 35 ft Form: rounded Type: deciduous tree Annual Growth Rate: more than 18 inches
Cultivars: 'Imperial' - A male clone, attains a roughly pyramidal shape with a height of 60 feet and a spread of 35 feet. 'Nor'easter' - This clone is a sterile female so will be seedless. It is listed as being more disease resistant than other poplar cultivars. It is a rounded tree reaching a height of 75 feet and a width of 40 feet. 'Prairie Sky' - A columnar form that will be 55 feet tall but only 10 feet wide. Cold hardy and vigorous. 'Robusta' - This cultivar is also seedless and forms an oval crown on a tree about 50 feet tall and 35 feet wide.