Tall, Deep Rooted Evergreens

Evergreen trees keep needles or leaves on their branches throughout the winter and range in height from 12 to 60 feet. Some varieties of evergreen will grow deep roots when planted in the right conditions. U.S. Department of Agriculture plant hardiness zones vary by variety of evergreen. The Colorado Blue Spruce, for example, grows in USDA zones 2 through 7. Evergreen species include Cedars, Pines, and Redwoods.

White fir (Abies concolor) evergreen trees

USDA-NRCS PLANTS Database / Herman, D.E., et al. 1996. North Dakota tree handbook. USDA NRCS ND State Soil Conservation Committee; NDSU Extension and Western Area Power Administration, Bismarck.

grow up to 50 feet tall by 30 feet wide. The depth of the roots vary with growing conditions. In high mineral soils with adequate water, roots of White Fir trees grow very deep. The pyramid-shaped tree has flat, blue-green needles. The tree is a moderately fast grower, and requires average to high levels of soil moisture. White fir provides habitat for wildlife, including deer, elk, bear, and bald eagles. This variety is not recommended for windy sites or in areas with clay soil. White fir is drought and heat resistant and grows best in U.S.D.A. plant hardiness zones three through seven.

Douglas fir (Pseudotsuga menziesii) evergreen trees grow up to 80 feet tall by 20 feet wide. In soil unobstructed by rock or other impediments, Douglas fir grows a deep tap root. The pyramid-shaped tree has flat, bright bluish-green needles. The tree is characterized by its unique 3 to 4 inch cones and three-pointed leaf bracts. It is a moderately fast grower. The tree requires excellent drainage, and grows best in clay and silt loams. Douglas fir is drought tolerant. Its seed provides food for wildlife, including chickadees, chipmunks, and deer.  It is found primarily in the western United States and is grown in U.S.D.A. plant hardiness zones four through six.

Eastern white pine (Pinus strobus)

Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA NRCS. 1995. Northeast wetland flora: Field office guide to plant species. Northeast National Technical Center, Chester

is a fast growing evergreen tree. It grows up to 50 feet tall by 20 feet wide. Though the tree does not have a significant tap root, three to four broad reaching roots grow out from the Eastern white pine to firmly anchor the tree. The broad, columnar-shaped tree has horizontal branching and fine, blue-green needles. The tree makes an excellent windbreak or screen. It grows best in moist, well-draining soils. Seeds of the Eastern white pine provide food for squirrels and songbirds. It grows primarily in the upper mid-western United States and thrives in U.S.D.A. plant hardiness zones three through eight.

Austrian pine (Pinus nigra) is a moderately fast growing evergreen tree. It grows up to 50 feet tall by 25 feet wide. Roots of an Austrian pine grow deep and lateral when the soil is unobstructed and loose. The broad, columnar-shaped tree has 3 to 5 inch dark green needles. The tree tolerates a variety of soil types and is tolerant of air pollution. Austrian pine grows best in U.S.D.A. plant hardiness zones five through eight.

Resources:
 USDA Natural Resoures onservation Service Plant Guide
Arbor Day Foundation