Ginkgo (Ginkgo biloba) is horticulture’s best-known living fossil. Abundant and cosmopolitan in the fossil record extending back 270 million years, the tree was thought long extinct by Western scientists. Then in 1690 botanist Engelbert Kaempfer (1651–1716) happened upon a small grove of living ginkgos growing in the garden of a Japanese temple. He brought seeds back to the Netherlands and planted them in the Utrecht Botanical Garden, where those 300-year-old trees remain today.
Unchanged for 270 million years, no other tree offers so direct a link to the past. Cambridge professor Sir Albert Seward (1863–1941) remarked: “It appeals to the historic soul: we see it as an emblem of changelessness, a heritage from worlds too remote for our human intelligence to grasp, a tree which has in its keeping the secrets of the immeasurable past.”
Every ginkgo leaf is living antiquity. They are the only leaves alive today that demonstrate the ancient pattern of dichotomous venation. That is, veins fork like the letter Y, eventually generating a bi-lobed, fan-shaped leaf. These distinctive leaves are apple green and flutter in a gentle breeze, so a large tree looks like an enormous maidenhair fern. They turn brilliant yellow in autumn and drop all at once as if on cue.
The name “ginkgo” is Chinese, meaning “silver apricot,” referring to the seed. While it would be easy to call these soft tan-yellow, plum-like structures “fruits,” ginkgo is so ancient it predates the evolution of fruit. It simply produces naked seeds, placing it among our most ancient gymnosperms—plants that produce naked seeds—and our most ancient of seed-producing plants.
Ginkgo trees are either male or female, with only males being recommended horticulturally. This is due to the seed’s oily covering, which is highly charged with butanoic acid, the same substance responsible for the smell of rancid butter.
As an exchange student in the late 1980s, I lived near the New Zealand city of Hastings, where the main street was planted with both male and female ginkgos. When the seeds fell in autumn, one could nearly skate through the oil slick on the pavement, while breathing in the strong, disagreeable odour of rancid butter.
Despite genetics unaltered by hundreds of millions of years, ginkgos survive tenaciously in the modern world. They thrive in today’s polluted cities better than almost any other tree, have essentially no insect or disease problems and withstand remarkable root crowding, growing well in pots. They are also very long-lived, with some in Asia thought to be 3,000 years old. Perhaps the most remarkable testament to their survival are four highly revered ginkgos growing in central Hiroshima. All were within two kilometres of the 1945 blast and while little else survived amid the holocaust, those four trees remain alive today, still bearing scorch wounds.
Saskatchewan falls just outside the hardiness range for ginkgo, but one should never underestimate the miracle of the microclimate. I know of a number of small ginkgos thriving within Saskatoon’s heat island. Two are on the University of Saskatchewan campus: the smaller in the southwest corner of the plot behind the Biology Building, and the larger at Innovation Place. It is tucked into an exquisite microclimate just outside the Sedco Centre doors that face west onto the pelican pool. The others are in private gardens around the city. Of those, I own two: one is presently emerging from its sixth winter in the backyard, and the other (the lucky twin) lives in a pot and winters in a 4°C cooler. Both continue to do well and provide a glimpse of living antiquity that can truly touch the historic soul.
Brian Baldwin was with the Department of Plant Sciences in the College of Agriculture at the University of Saskatchewan. Since his passing, I am not sure what happened to his potted Ginkgo, nor the fate of the tree in his yard. I did venture out to the University of Saskatchewan today and found the tree at the Atrium at Innovation Place doing well. It was unclear from his description in the article as to the exact location of the second tree on campus. There has been some construction in that area, with new pathways, etc. I was unable to find the smaller tree.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.
