ASK THE HORT AGENT
Question Which tree provides good fall color?
Answer One of my old favorites is the “Maidenhair Tree” or “Ginkgo” (Ginkgo biloba), and I do mean old. Ginkgo is considered the oldest tree species on earth. Earliest leaf fossils date back 270 million years ago to the Permian period. Ginkgoes flourished during the time of the dinosaurs (Jurassic 213 million years ago). Fossil leaves show there were several species. During the Middle Jurassic there was a great increase in the number of species. Maximum diversity was during the Cretaceous period (144 million years ago) in areas now known as Asia, Europe and North America. These trees were common and widespread for a long time.
Due to global cooling, only three species were left (Ginkgo biloba, Ginkgo adiantoides and Ginkgo gardneri) in the Tertiary period (65 million years ago). The loss of dinosaurs as seed dispersers probably contributed to their decline. About 7 million years ago the Ginkgo disappeared from the fossil record of North America. It was gone from Europe by about 2.5 million years ago. Luckily, Ginkgo biloba survived in China.
Individual ginkgo trees also compete for the title of oldest living thing on earth. There are 180 trees in China over 500 years old. A few of them are approximately 3,000 years old.
These trees are long lived, because of their resistance to diseases, insects and fires. They are also extremely tolerant of air pollution and drought. These traits make them suitable for urban environments where most other trees will not survive. In August of 1945, a ginkgo tree was growing by a temple in Hiroshima, Japan. One of the atomic bombs was detonated just over one half mile from this tree. The temple has been rebuilt, and the tree is still growing today. Tough enough?
Most varieties of ginkgo trees are large (between 75 and 120 ft. tall). While these trees are great for parks and open areas, homeowner space is sometimes limited. Several dwarf varieties have been breed – ‘Spring Grove’ (12 ft.), ‘Jade Butterflies’ (12 ft.), ‘Munchkin’ (4-6 ft), ‘WB’ (10 ft.) and ‘Mariken’ (4 ft.).
Ginkgo leaves have a wonderful yellow (almost gold) fall color. When the leaves fall from the tree, it appears as a chest of gold has spilled on the ground. It is truly miraculous to gaze upon the same yellow leaves that dinosaurs viewed.
Besides aesthetics, ginkgo trees have medical uses. While some research is conflicting, Ginkgo extract may have three effects on the human body: improvement in blood flow to most tissues and organs, protection against oxidative cell damage from free radicals and blockage of many of the effects of platelet-activating factor that have been related to the development of a number of cardiovascular, renal, respiratory and central nervous system disorders. http://www.umm.edu/altmed/articles/ginkgo-biloba-000247.htm
For more info on ginkgo trees, visit http://hcs.osu.edu/hcs/TMI/Plantlist/gi_iloba.html If you don’t have internet access then call me at 910-893-7533 or email me at email@example.com Ginkgo trees handle snow loads as well as heat. They lived through the ice that killed the dinosaurs. It appears they will live through the heat that kills the polar bears.
Gary L. Pierce
Horticulture Extension AgentHarnett County