Hybrid poplars are among the fastest growing of all the trees in the temperate, colder areas of the Northern Hemisphere, making them a popular choice for landscape shade. Hybrid poplars are the result of cross-fertilizing or cross-breeding two species. These hybrids are usually more resistant to disease and environmental stress than their parent species.
Hybrid poplars are the result of a cross between trees from the Populus species. The parent tree is often a cottonwood (Populus deltoides) or the black poplar (Populus nigra). Growers cross those trees with the balsam, Japanese or Russian poplar, among other varieties. Hybrid poplars derived from the cottonwood carry the classificiation Populus x euramericana.
Leaves are usually green to dark green, turning yellow in the fall. They measure 2 to 5 inches in length and width. Hybrid poplars produce small brownish-red flowers in the spring along with catkins. Hybrid poplars can also produce light brown seeds encased in cotton-like fiber. Young hybrid poplars have gray-green trunks. As the tree ages, its trunk turns dark gray and the smooth bark becomes furrowed.
Hybrid poplars grow up to 5 feet to 8 feet a year, reaching 40 feet to 60 feet high. Their branches can spread 20 feet to 35 feet, not as broad as the cottonwood's spread. These hybrids usually feature a pyramidal or columnar shape.
Hybrid poplars make good landscape accents. Planted in rows, they can serve as windbreaks. They also make good nesting areas for birds and provide cover and food for animals. Birds eat the buds, and deer, rabbits, mice and beaver eat young twigs for food. Other uses for hybrid poplars include as a source of pulp, firewood and salicin, a headache and fever remedy.
Hybrid poplars are hardy from USDA Plant Hardiness Zones 3 through 9. They prefer clay loam and sandy loam soils with a pH of 5.5 to 7.5. Plant hybrid poplars in a moist area, since they do not tolerate drought well. Hybrid poplars are susceptible to diseases such as Melampsora leaf rust and Septoria leaf spot and canker. Insects that attack hybrid poplars include the poplar borer, poplar leaf beetles and poplar gall mite.