Written by davethetreecenters • April 23 Grow Living Fossil Trees in Your Garden
Most of us grow plants in our gardens simply for their beauty, and that surely is the best reason of all. But many plants also have a story to tell, perhaps of how they were first found, or the uses people have made of them – or sometimes about their amazing histories. Knowing these stories makes our plants more interesting and enriches the experience of our gardens. Some of the most fascinating stories are about trees that are orphans from a distant past. These are often called Living Fossils, because they are trees that once flourished across the planet and had many relatives just like them, that are now long gone. Today these trees are rare and found only in a few places, the last survivors of previous ages that now only exist as fossils in rocks – except for these remarkable plants.
Choosing a Living Fossil tree for your garden gives you something beautiful and useful, but it also helps preserve these amazing plants, makes your garden more interesting to contemplate, and introduces your family to the wonders of the world around them. These trees are not hard to grow, and they are beautiful additions to any garden on their own merits, so why not plant a Living Fossil this season?
The Ginkgo Tree
In 1691 a German naturalist and explorer called Engelbert Kaempfer was one of the first Westerners to visit the then-mysterious kingdom of Japan. While visiting a Buddhist monastery in Nagasaki he saw a remarkable tree he had never seen before. He was given some seeds, and he in turn gave them to the botanic garden in Utrecht. They grew and were officially named Ginkgo biloba almost a hundred years later, by the famous botanist Carl Linnaeus. The name ‘Ginkgo’ is probably an error in Kaempfer’s notes, as it is called gin-kyo in Japan. The original tree in Utrecht is still alive, and it can be seen in the picture above. For a long time it was believed that the tree was extinct in the wild, kept alive only by temples in China and Japan. However at least two wild populations have been found still growing in Zhejiang province in eastern China.
This beautiful tree grows 40 to 50 feet high, with a spreading crown up to 30 feet across. It is a beautiful shade tree for a lawn, and despite its age it is very resistant to modern city conditions, and so it is often seen as a city street tree in large cities. It has beautiful rounded leaves with unique fan-like veins, that make it easy to recognize, and the heavily-textured gray bark gives it a solemn air that suits its ancient heritage. This tree’s most spectacular feature is the fall coloring, when the whole tree turns into a palette of pure gold, glowing in the fall light. Individual trees vary in the intensity and purity of the coloring, so it is best to choose a named variety. One of the best is ‘Autumn Gold’, which not only has vibrant and reliable colors, but is a male tree. Female trees produce fruit with a pungent, unpleasant smell, so they are rarely grown. Seedling trees can of course be either, and you won’t know until it is mature. Not only is the Ginkgo tree resistant to cities, it is also very hardy, right into zone 3, yet growing well even in zone 9. There are very few places in the country where this tree cannot be grown.
Fossils very similar to the Ginkgo tree have been found that are 270 million years old. At that time flowering trees had not yet evolved, and only conifers, which Ginkgo is related to, existed, and they were new on the earth. There were just two continents, which had not yet broken up into those we see today, and CO2 levels were more than double what they are today. Dinosaurs were everywhere, and the early mammals had just appeared. What a very different world the Ginkgo tree was born into!
The Dawn Redwood
If we move the planet fast-forward from 270 million years ago to just 50 million, we find a world where the North Pole was almost as warm as Florida, but still dark during the months of the long Arctic night. Much of North America was covered in forests of Redwood trees, and fossils show they were three types. Two of them, Sequoia, the coast redwood, and Sequoiadendron, the giant sequoia, still exist, in the dwindling redwood forests of California, where they are justly famous for their enormous size. The third, Metasequoia, was believed to be long-extinct.
In 1941 China was occupied by Japan forces, and war raged. But life went on, and in a tiny village called Mo-tao-chi a Chinese forester discovered a group of strange, deciduous conifers growing. With the vagaries of war, he was unable to do much more than inform a local schoolteacher, who later reported the trees to scientists. After a long saga of fruitless attempts to identify this mystery tree, a top expert solved the puzzle. In 1946 Professor Hu, noticed the similarity to Metasequoia, which had been described from fossils by Shugeru Miki, a Japanese authority on fossil trees. By coincidence he published the description in 1941 – the same year the first live trees were seen.
Word of this discover reached the Arnold Arboretum at Harvard University, and $250 was sent to China to finance an expedition to collect seed from this remarkable tree. Over a thousand trees were found growing in the area around Mo-tao-chi, and in early 1948 seed arrived in America and was quickly germinated at the Arboretum. The arrival of this living fossil was heralded in the press, and a new tree was introduced to American gardeners.
The Dawn Redwood, Metasequoia glyptostroboides, is a fast-growing tree that can add 2 feet to its height every year, reaching 40 to 50 feet in height in about 30 years. It remains narrow, perhaps 20 to 25 feet wide. It has a strong central stem, and more-or-less horizontal side branches. The narrow needles resemble those of the yew tree, and they are in two parallel rows along the stems. Almost all conifers are evergreen, but this tree drops its leaves it winter. This is believed to be a natural response evolved to deal with the long ‘Arctic’ winter, although of course the temperatures were not particularly cold when the tree first appeared. This tree is easy to grow in most gardens, and it is hardy to zone 4. It makes a wonderful lawn specimen, or a background tree, and it is certainly a conversation piece.
These two living fossils, both growing in China, are amazing ‘left-overs’ from pre-history, one from the age of dinosaurs, another from a period of high temperatures perhaps not so different from the one we are headed into now, if we do not stop global warming. Not only are they beautiful, but the remarkable stories of their discovery and introduction make them more than just plants – but also part of our culture and heritage.
