The ginkgo tree is known for its unusual fan-shaped leaves, its longevity and remarkable pest resistance. Young trees are columnar in shape, have few branches and appear out of proportion. This gawkiness changes as the tree matures. Its foliage becomes dense and branches spread out. It is hardy in zones 3 through 8.
The scientific name for the ginkgo tree is Ginkgo biloba. Common names are ginkgo and maidenhair tree. Mature trees reach a height of 50 to 80 feet and a width or spread of 50 to 60 feet. The shape of the crown is an irregular pyramid or sphere, and its growth rate is slow. The leaves are from 2 to 4 inches in length. Foliage is green throughout spring and summer, turning yellow in the fall. Fruit and flowers are inconspicuous. The flowers are green in color and have a pleasant scent. The ginkgo tree is dioecious, which means that male and female flowers are borne on separate trees. Cultivars are often selected for male fruitlessness, as stated by Ohio State University Horticultural and Crop Science Department. Tan-orange fruit (on female trees) is oval in shape and 1 to 3 inches in length. Fruit can be a maintenance concern because it becomes quite messy in the months of September and October. The fallen fruit also has a strong malodorous scent.
Several cultivars are available, each having its own characteristics. Male fruitless cultivars are Autumn Gold, Fairmont, Fastigiata, Lakeview, Mayfield and Princeton Sentry. The Princeton Sentry also has a narrow conical crown, making it perfect for spaces with low overhead. Variegata is a cultivar that has variegated leaves.
The ginkgo tree requires a site with full to partial sun. This tree will tolerate most soils, but it prefers moist, deep sandy soil. It tolerates salt spray, air pollution and drought and is pest and disease free. Pruning requirements are minimal; you will only need to prune to remove dead or damaged branches, to maintain size within your landscape or to provide clearance if the tree is planted near a walkway or driveway.
Ginkgo trees can be used as shade trees, specimen plantings or focal points in your landscape design. It appears to be the perfect urban tree, but it is much too large to be planted along city streets.
The word "ginkgo" comes from the Japanese word "ginkyo," meaning "silver apricot." This unusual tree has been on earth for more than 150 million years. At one point in time it was thought that the ginkgo tree was extinct. But in the mid-1700s it was found in China. Today the ginkgo tree is found in urban and country landscapes throughout the world.