Linden Greenspire is a cultivar of littleleaf linden tree (Tilia cordata Greenspire). Noted American woody plant expert Dr. Michael Dirr of the University of Georgia says this linden trees is "truly a cool-climate shade and street tree." Grow it in U.S. Department of Agriculture hardiness zones 4 through 7. Both Dr. Dirr and the University of Connecticut attest that Greenspire is the most popular selection of littleleaf linden tree in the United States.
Littleleaf linden is native to Europe's forests. Its natural range extends from southeastern England and across most of Scandinavia and the eastern half of the European continent. A tree with an exceptional pyramid-like canopy and branching structure that grew from a strong central leader (upright growing tip) was selected and assigned the cultivar name Greenspire.
Both print and online resources vary the mature size of the Greenspire linden, probably because of small variations in growth from climate and soils. Generally, this tree matures between 40 and 75 feet tall and 35 to 40 feet wide, based on commentary from the U.S. Forest Service, University of Connecticut and Minnesota Department of Transportation.
The glossy medium to dark green leaves of Greenspire are tapering broad ovals that look somewhat heart-shaped. In late spring to midsummer, depending on climate, the tree is filled with thousands of tiny yellow-white flowers that are deliciously fragrant, attracting honeybees for pollination. Later, small, pea-sized fruits called druplets or nutlets are formed and drop the ground attached to a stalked bract. In fall, the leaves turn varying shades of yellow and gold before becoming brown and dropping off.
Plant linden Greenspire in a sunny location where it receives no less than eight hours of direct sun rays daily. For best growth, littleleaf linden trees prosper in a moist, deep and fertile soil that has good drainage. Greenspire is widely adaptable, growing in typically "difficult" landscape conditions such as heavy clays that are quite dry as well as soils that are neutral to alkaline in pH. It is tolerant of air pollution, too, warranting its use in urban settings.
Serious problems occur on Greenspire and must be weighed against its adaptability to a variety of landscape applications. Japanese beetles readily decimate the foliage of the tree and the U.S. Forest Service advises to not plant it where these beetles are widespread or commonplace each summer. Aphids and their honeydew excretions lead to sooty mold on foliage. The Minnesota Department of Transportation states that Greenspire has serious root system issues, primarily with stem girdling. Stem girdling is a condition when roots at the trunk base encircle or wrap around each other and then grow and enlarge to constrict their flow of sap. It eventually causes sections of the tree to die, eventually the entire plant if the flow of sap and nutrients is fully blocked.