Spring is almost here in New England and along with the robins comes an explosion of scent as the earth begins to thaw and the plants to bloom. In the spirit of recognizing the less commonly admired natural phenomena, lets talk about some stinky trees!
The first tree on my list is the common Boxwood, varieties of which can be found in both tree and hedge form. Native to several different
continents, the boxwood is an ubiquitous presence in yards everywhere in the US. Frequently used to grow whimsical topiaries for the super rich, it also has the distinction of helping create the ridiculous industry of plant hairdressing. An evergreen with tiny leaves instead of needles, the boxwood is a favorite for creating hedges between properties or adding some curb appeal around a home. Throughout fall and winter the boxwood is a rather innocuous presence but trouble brews as the temperatures begin to heat up. When the oil in the boxwood leaves reaches a certain point-POOF. Out comes an acrid stink which many describe as “cat pee”. Interestingly the exact nature of the
boxwood’s scent seems to be a pretty polarizing topic on the internet. Many claim to”love the smell”, that it reminds them of “summer during childhood” or often that it is simply “earthy”. These people it should be noted are most certainly delusional because I can tell you the plant unequivocally reeks of cat urine-sniff one for yourself this August. It’s not just me either: this claim is backed up by many people who would have a vested interest in the topic: realtors. There are many anecdotes from both realtors and sellers reporting a struggle to sell homes with boxwoods planted in the vicinity; buyers were convinced there was a band of roving cats relieving themselves in the shrubbery.
The next tree on the list is one I don’t have any personal experience with but has too good a story to pass up, let us consider the Ginkgo tree. Originally native to China, ginkgo biloba has been used for centuries for medicinal purposes and it’s seeds harvested for use in traditional Japanese and Chinese cooking (once roasted they are described as having a sweet flavor and chestnut like texture, but beware-eating too many or eating them over a long period of time can cause poisoning). The ginkgo tree made its way to the US from Asia over two hundred years ago. Prized for it’s unique foliage and natural fortitude, the ginkgo is a hardy ornamental resistant to
pollution, disease and even nuclear fallout (6 ginkgo trees were among the only living things to survive within a 2 km radius of the bomb dropped at Hiroshima). In many ways this tree is pretty magical:it feeds us, gives us medicine, is easy on the eyes and apparently invulnerable. However, there is a big catch-remember those nuts that people have been collecting for thousands of years? Yeah well those nuts are encased in a light yellowish brown flesh that once fallen from the tree begin to emit the pungent stench of vomit. Also described as
“rancid butter” or “overaged parmesan cheese”, the ginkgo’s odor is caused by the presence of butyric acid, which is indeed the fatty acid found in human vomit, milk and milk products. Fortunately only the female trees produce the fruit, and only then if they are planted in close
proximity to the male trees. Originally cities and municipalities attempted to plant only male trees, however when the trees are young it can be difficult if not impossible to determine their sex. To complicate the matter further the females do not begin to produce fruit until they are around 25 years old so it is generally a shock when an established neighborhood landmark suddenly begins dropping a profusion of stink bombs after two decades of relative inactivity. Alas, in a few more decades this puke-y funk may only be a memory as nearly all of the ginkgo trees planted in the US today are grafted in an attempt to ensure all future ginkgo trees are male.
Third and final in my stink-tree line up is the great American Chestnut, a tree for which I have a particular fondness. Much of my compassion for the chestnut comes from the fact that as a species it has had a rough go. Once a commonly used hardwood timber tree, the great chestnut blight of the early 20th century wiped out an estimated 3-4 million trees, making adult specimens a relatively rarity. I was lucky enough to have grown up near one of these trees and more than the edible nuts inside, my sister and I were fascinated by the growth of their spiky pods. The pods would grow as large as an orange before splitting open (just like in the Alien movie) spilling their contents to the Earth. Once the nuts were gone the tree quickly cast off the obsolete husks and we would collect them, probing their sharp spikes with our finger tips and marveling at the heft of
these massive, otherworldly growths. There are many things about the American chestnut that make it interesting: their rarity, unusual seed pods, and tragic past are just the beginning. In my opinion it is their aroma that is their most noteworthy and distinctive attribute. On warm summer nights, when the male flowers (called catkins) are in bloom you will catch a
whiff on the wind and immediately think, “what the…chlorine? No.Wait. Oh my god, I know that smell.. it’s semen.” That’s right, the American chestnut smells like semen. Described as “pungent”, “an acrid tang” or as one colorful arborist suggested “like a whore house on a hot summer’s day”, the scent of the American chestnut appears to be universally reviled. Although I couldn’t find any definitive explanation for the smell, it is probable that both semen and the chestnut have some similarities in their chemical make up-likely ammonia or some other sterile-smelling alkaloid. Surprisingly this scent phenomenon seems to be relatively common in the plant world. In researching the American chestnut I also stumbled upon the Callery Pear and The Tree of Heaven, more common trees whose seedy odor has attracted a veritable cult of detractors extending from the West Coast to New York City and the small towns of Western Massachusetts.
Flowers like roses, lilies, and jasmine seem to get all our consideration when we reflect on the world of botanical odor but there are indeed a myriad of other plants sending their essence into the world with no regard for how we humans feel about it. I for one enjoy the diversity of scents in the world and wouldn’t have it any other way. And as always remember: a rose has never smelled so sweet as when you’ve just had a nostril full of plant jizz.