If you are thinking about what to plant to replace that large ash tree in your landscape, consider the Ginkgo biloba. This tree is also known as the maidenhair tree because its leaves closely resemble the leaflets of the maidenhair fern. It has a fascinating history, thrives in even adverse conditions, and is resistant to almost all insects and diseases.
Ginkgo trees are ‘living fossils.’ The species Ginkgo biloba has no living relatives, but closely related trees populated the earth during the time of the dinosaurs over 180 million years ago. Fossils of these trees can be seen in Ginkgo Petrified Forest State Park in Washington State. A small number of trees survived to the present day in China where they were worshiped and venerated. They are now widely planted throughout the world as beautiful specimen trees. Even though they have leaves, they are the only living link between ferns and conifers.
The leaves of the ginkgo tree are very distinctive. They resemble small fans on stems almost as long as the leaf. This makes the tree seem to shimmer in the wind. The leaves are often divided into two lobes by a cleft down the middle, thus their name ‘biloba.’ The leaves usually form in clusters at the ends of short spur stems off the main branches, but on longer stems they alternate up the stem. They turn a beautiful yellow color in the fall, and the trees commonly lose all their leaves within one or two days, covering the ground with a golden carpet of small fan shaped leaves.
Ginkgo trees are very hardy, while they prefer full sun or partial shade and sandy loam, but they will grow in both alkaline and acid compacted soils and will withstand drought, salted roads, wind and even fire. But do not plant them in a wet area, they do not like to have wet feet. Because they are resistant to insects and most diseases, they are commonly planted as street trees and survive in this difficult environment. Four Gingko trees even survived the bombing at Hiroshima, surviving about a mile from the epicenter.
The Ginkgo tree is dioecious, that is there are male and female trees. Only plant grafted trees that are known to be male plants. Female trees that are more than 20 years old produce a large crop of nut-like seeds encased in a vile smelling, soft fruit-like covering. The cooked nuts are prized in Japan and China and are said to have medicinal qualities in these cultures. In Western medicine it is the leaves that are used as herbal preparations. Ginkgo trees are not true flowering plants, the pollen on the male plants is carried by the wind to the female plant where it must land in a water droplet because the sperm must swim to the female ovule to pollinate the plant.
Ginkgo trees are easily transplanted and have a slow to medium growth rate depending on cultural conditions. They cast light to moderate shade. They can seem sparsely branched and gawky when young, but their crown will fill out as they get older. Because they are slow growing, they can be considered a medium sized shade tree for the first 50 years or so, after which they may outgrow a small space. If you want to leave a lasting legacy, plant one of these trees in a spot where they have room to grow. For the next several hundred years, the tree will only become more spectacular. Mature trees can be nearly 100 feet tall and 60 feet wide and are very long lived. There are trees known to be over 1000 years old in the Far East.
Consider planting the cultivar ‘Autumn Gold’ as it is reliably male and has a dependable yellow fall color. It matures at a relatively compact 50 feet tall and 30 feet in diameter.
For more information on home, lawn, indoor, or outdoor garden care and tips, as well as other garden topics, visit www.ohioline.com and click on the Yard and Garden link, or call the OSU Extension, Butler County, at (513) 887-3722, or in Middletown at (513) 424-5351, ext. #3722.
News Release provided by Kathy Maurer.