When the average Mary walks by a gingko biloba tree, she sees nothing unusual. But anybody who has a mind for horticulture and walks by a gingko sees a truly odd tree.
Start with the leaves. Gingko (sometimes spelled ginkgo) is the only deciduous conifer I know that has dichotomous veins. While all other leaves have veins that are networked throughout the leaf, the veins of gingko are straight and parallel to each other, just like corn and grass. Gingko biloba often goes by the common name of maidenhair tree, a name given because of its leaf shape.
Gingko trees are dioecious, meaning there are both girl and boy plants. Some would think the list of dioecious plants is vast, but gingkos share space on the dioecious list only with such common plants as holly, mulberry, asparagus, junipers and spinach.
Gingko trees stink. But, oddly enough, only the girl stinks. And she only stinks in the fall when she drops her nut-like fruit. Only when the gingko is mature does she begin to stink. It is not a horrible smell, but think of dirty socks left in a gym bag over the weekend.
Nurseries and gingko growers have the stinky female problem licked because they will only grow males. Even in the wild, there are no stinky gingkos.
Gingkos don’t grow in the wild. They are the furthest thing from native as you can get. Gingko trees are a species of tree native to China.
Gingko trees are sometimes referred to as fossils and are the only living species that can be traced back to the middle Jurassic era, north of 150-million years ago.
Leaves of gingko are true green, turning bright yellow in autumn. Their leaves drop when they are ready and not a moment earlier. I have seen gingko leaves survive a wicked windstorm only to gently fall the next morning. Oaks and beech drop their leaves over a period of weeks and months, but gingko leaves will drop within days or even hours.
Gingko trees are widely planted, and sit comfortably in the hardiness plant zone 3, meaning they will grow through Europe, Asia, through most of the United States and north to Sudbury. Their resistance to disease and insects, tolerance of any soil and ability to withstand city conditions make them long lived. Gingko trees are popular as street trees in urban environments, where growing traditional trees poses a challenge.
Gingko trees are tall and moderately fast growing, reaching heights of well over 50 feet. Sarnia-Lambton is home to many gingko trees, including a cluster in Germain Park, just beyond the greenhouse. Another stately group of gingkos are growing nicely in the boulevard at the five corners of Ontario, Mitton and Wellington streets.
As with many most trees, horticulturists have come up with versions of gingko trees with unique characteristics. Autumn gold is a smaller tree, with less width and height and with improved fall colour. Folkerts select is a smaller tree with smaller leaves than its parent plant. Mariken dwarf is a tiny variety growing only a few feet high with dense, spreading branches. Gingko biloba troll can be trained to become a pyramidal tree or a small tree shaped like a lollipop. Gingko Princeton sentry becomes tall and narrow and is suited for smaller backyards.