We love University of Minnesota horticulturalist Jeff Gillman here at the Rant because he brings news from the world of science to this blog, because he contributes a scientific skepticism to gardening in general, and because he is one of the few scientists who actually bothers to talk to gardeners.
But we never thought we'd love him because he's a poet. We were wrong. Give him a subject worthy of poetry, and he rises to the occasion. His new book How Trees Die: The Past, Present, and Future of Our Forests is at once delightfully informative and disturbing and profound.
Jeff Gillman being Jeff Gillman, How Trees Die offers all kinds of knowledge that will have you wondering where you've been all these years. Here are a few bits from a chapter called "Apples and Age" that deals with the peculiar fact that vegetatively propagated plants can be old and young at the same time.
- "Though a plant grown from a cutting may seem young, the meristem of this little bit of plant may actually have been around for a long time. In fact, this little piece of plant material may easily be forty or fifty years old, though the plant in your garden has existed only for a year or two. Over time that little piece of plant will accumulate mutations, or problems with its DNA, which may or may not affect how the plant grows."
- "There is, in strawberries, a disease affecting some varieties and not others called June yellows…. It seems to be a genetic disease triggered by age. Every plant of a variety which has June yellows is a time bomb. And since every plant is propagated asexually, and are almost exactly the same age, all of the bombs are set to go off at once…. Wham! There goes that variety of strawberries."
- "As the tree grows up, it matures. The growth that has already been deposited, the part of the tree trunk near the earth, will stay relatively young while the growth near the top, though it may be newer chronologically, will be physiologically older because the tree is programmed to mature as if it grows, and the only way for this to happen is for the new growth (chronologically) to be more mature than older growth….Cuttings taken from locations closer to the top of the tree will produce trees that are physiologically older, while cutting taken from closer to the base of the plant will produce trees that are physiologically younger."
I learned many other weird and shocking things from How Trees Die, including the mind-blowing fact that there were no earthworms in the Northeastern United States until they arrived in the ballast of European ships.
But I also found myself musing about mortality and the blundering stupidity with which we humans move through nature and the fact that we know so little about the trees to which we instinctively compare ourselves in their quiet dominance of the landscape. And maybe, by extension, we know relatively little about ourselves, too.
This is not where I usually end up after reading a gardening book, but How Trees Die is no ordinary gardening book. It is an entirely amazing piece of writing. Don't miss it.