Are you Gaga for Ginkgos?
By SCMG Bill Klausing
It’s not often that you can plant a living fossil in your own garden. Ginkgo biloba is just that. Ginkgos are the oldest living tree species on the planet; even our own majestic old growth redwoods cannot hold a candle to the ginkgo’s lineage. 200 million years ago they grew across a variety of continents; now their naturalized occurrence is limited to a few distinct areas of China. The ginkgo is most closely related to conifers, rather than any of the deciduous trees commonly found in our landscapes; its closest genetic relatives are actually cycads and ferns. A frequently used common name for the ginkgo is the maidenhair tree. If you get the opportunity to closely examine the fronds of a maidenhair fern, you will find the leaf shape and veining structure of the ginkgo to be almost identical.
Ginkgo biloba is a notoriously slow-growing tree, although in optimal conditions may grow as much as three feet per year. Early in its life, the ginkgo will appear lanky and leggy, with a non-distinct canopy shape. As it matures, the canopy will expand to about half of the tree’s height. Its genetic history is evident in its ability to thrive in a variety of conditions: wet, dry, alkaline soil, acidic soil and poor air quality. These qualities make it a perfect selection as a
street tree in suburban settings where less than ideal growing conditions can be present. The ginkgo is present on several Sonoma County municipalities’ short-lists of approved plantings for these very reasons.
The ginkgo is dioecious, which means that there are male and female trees, with the fruit borne on the female. The female ginkgo generates foul-smelling fruits so the male is the tree of choice for landscapes around the world. Nursery stock is generally grown from grafted specimens or simply from propagated cuttings. Locally, the crew at Jail Industries provides inexpensive propagated saplings at their sales during the spring and fall. The soft green leaves of a ginkgo have a celadon tint, and wave beautifully on a nice breezy day. In the fall, the leaves change to a florescent gold before quickly dropping after a two to three week show of color. In Santa Rosa you can find a
very nice stand of ginkgos along McDonald Avenue where their use as street trees can be seen to great effect. You’ll find the fall color in Ginkgo biloba develops shortly after Halloween, and the leaves drop cleanly by early December. A tip of the cap to one of the planet’s most durable survivors …..