The ginkgo tree, also known as the maidenhair tree or by its scientific name, ginkgo biloba, is an introduced deciduous tree from Asia. It is considered a living fossil, as the fossil record shows that ginkgo trees have been around for hundreds of millions of years. This pest-resistant and tough tree is often found in urban environments as a landscape tree. The plant is also used for medicine.
The ginkgo tree has characteristic fan-shaped leaves that are deeply veined, around 2 to 4 inches long. They are light green in the growing season and turn a brilliant color of yellow in the fall. Ginkgo produce separate male and female plants. The flowers are small and insignificant. Female plants produce round, hard, fleshy, yellowish-green fruit on short stems in the fall that produce a rather foul odor.
This tree grows slowly, usually adding less than a foot of growth per year. Ginkgo may grow very slowly when first getting established, then the growth rate may increase as the plant matures. It grows well in hardiness zones 4 through 7 and is found commonly in the northeastern United States. It is not recommended for areas that receive a significant amount of heat for long periods of time.
The shape of ginkgo trees is round to pyramidal and is frequently irregular. The tree can reach a height of 75 feet and can spread to 60 feet across. The crown is open and airy with a medium texture. Ginkgo trees have relatively heavy branches and trunks which can reach 2 feet in diameter. Female plants spread more broadly than male plants.
Ginkgo trees prefer full sun to partial shade. Soil can be acidic or alkaline and sandy loam to clay. The tree can tolerate excessively wet or dry conditions for a short period of time. It is an excellent tree for urban environments, as it is very tolerant of air pollution, salt and depleted urban soils that may be heavily compacted. Propagation is almost exclusively by cuttings. Male plants are preferred, due to the fruiting habits of female plants. The tree is easily transplanted and should be well watered while it is getting established.
Ginkgo trees are commonly used in municipal plantings to line streets, median strips, around parking lots and in other urban settings. It also makes an excellent accent tree in the yard and can even be trimmed to form bonsai. An extract of the plant is used medicinally and is touted as improving mental function and memory.