The Four Fastest-Growing Trees in Zone 4

Poplars

• These trees are be called poplars, cottonwoods or aspens, depending on species. The fastest- and largest-growing tree in the lot is the Eastern cottonwood (Populus deltoides), with a vase-shaped silhouette with irregular, spreading branches. The Lombardy poplar (P. nigra "Italica") grows just as quickly but attains a columnlike silhouette. The robusta poplar (P. x robusta) works as a shade or windbreak tree for about 15 years before it succumbs to decline or death.

Maples

• Maples include two species with exceptionally fast growth rates for landscapes in USDA zone 4. The boxelder (Acer negundo) grows fast but becomes an irregular-shaped tree with weak wood. It's rarely grown as an ornamental tree but does make an inexpensive and effective windbreak tree. Female boxelder trees attract annoying boxelder bugs. The other fast-growing maple is the silver maple (A. saccharinum). Growing broader and taller than the boxelder, the silver maple develops a rounded, attractive canopy. It's suitable as a shade tree on a spacious property, but keep it away from roads and buildings, because it too is weak-wooded.

Locusts

• Two genera of trees in the legume family grow quickly and are winter-hardy in USDA zone 4: Gleditsia and Robinia. Honey locusts (Gleditsia spp.) become stately, attractive, small, shade trees with knobby branches. Most modern cultivars lack thorns and don't produce seedpods. The black locust (Robinia pseudoacacia) does carry thorns on its branches and produces showy, white flowers in late spring. In the northern U.S., black locust typically doesn't get large because borer insects usually destroy the trees before they reach more than 20 feet tall.

Elms

• American elms were wiped out from Dutch elm disease in the 1970s and '80s across North America, so planting one isn't a good long-term choice. A fast-growing relative worthy of use as a screen or windbreak is the Siberian elm (Ulmus pumila), which is commonly but incorrectly called Chinese elm in the upper Midwest. Siberian elm is slightly susceptible to Dutch elm disease. Even when healthy, this elm in not ornamental and looks unkempt.