Soon the lovely green fan-shaped leaves of ginkgo trees will turn a stunning shade of yellow. And then one night when the temperatures drop to a certain level, all the leaves will cascade down, carpeting the ground. No other tree on the planet has leaves like this, with its parallel veins and unique shape.

In fact, Ginkgo biloba has no close relatives. That fact along with an ancient lineage makes this species a "living fossil." Like its distant conifer cousins it is considered a Gymnosperm. Ginkgos are also dioecious, meaning that there are separate male and female trees. Pollen from a male tree is carried by the wind, and when it comes in contact with an ovule on a female tree, the fertilization process begins. Seeds with a fleshy outer covering develop on the female trees, and when they ripen and fall to the ground, the flesh develops a putrid odor.  It is for this reason that male cultivars are preferred for landscaping purposes. 

During the age of the dinosaurs several species of ginkgos were found  across the northern hemisphere. All that remains today is a small relict population in China. But the ginkgo has been revered in China for thousands of years and has long been cultivated in temple gardens in both China and Japan. Ginkgo trees were first cultivated in Europe in the 1700s, and have become well-established in botanical gardens and arboretums in Europe and North America. Because these trees tolerate a wide variety of conditions and have few problems with pests or diseases, they are favored in home gardens and commercial plantings, and are often used as street trees.

Numerous cultivars of Ginkgo biloba have been developed, offering wonderful selections for any garden. 'Mariken' and 'Chase Manhattan' are charming small cultivars that grow only 2-3' every 10 years. 'Princeton Sentry' has a narrow upright form, while 'Jade Butterfly' is vase-shaped. 'Pendula' and 'Weeping Wonder' cascade gracefully. Instead of lying flat, the leaves of 'Tubiformis' develop as little cylinders, while 'Saratoga' has a split leaf. Ginkgos thrive in full sun conditions and can be planted from zone 4 south to zone 8 or even zone 9.

Suggestions for further reading

Ginkgo: The Tree That Time Forgot by Peter Crane 

Ginkgo biloba in Japan by Mariko Hando

Landscaping with Conifers and Ginkgo for the Southeast by Tom Cox & John M. Ruter

The Living Dinosaur by Jill Jonnes