In many gardening circles, the mere mention of bamboo is enough to cause nightmarish shivers. Visions of voracious overgrowth devouring shrubs, birdbaths, and toolsheds inevitably haunt the mind. Here at the Arnold Arboretum, our largest stand of bamboo (Phyllostachys dulcis, accession 1019-89) covers a slope on Peters Hill, where it was planted thirty years ago. As early as 1993, curatorial staff cautioned that this planting of sweetshoot bamboo was “out of control,” and observed that the mass was “on its way to Roslindale.” Yet, no matter, the bamboo prevents soil erosion on an exceptionally steep slope—an important task that few other plants would accomplish with such brio—and so the mass remains, with a regular dose of horticultural muscle to ensure it continues to play within bounds.
Come winter, when the ground at the Arboretum is crusted with snow and my nose has retracted into the protective warmth of my parka, I’ll admit, too, that the green presence of our bamboo accessions offers a fond reminder of warmer months. Given that most of the world’s fourteen-hundred-odd bamboo species hail from tropical and subtropical regions, it’s easy to forget that many of the hardiest species are, in fact, evergreen and exceptionally tough. The sweetshoot bamboo on Peters Hill was pruned to the ground this fall, but another mass from the same source (accession 405-68) grows behind the linden collection, where the green leaves seem unfazed by a recent glaze of frozen rainwater. If you stand close and gaze between the knuckled stems, which tower more than twenty feet high, winter (almost) fades like a distant memory.
To my mind, however, the most interesting accession in our bamboo collection is Arundinaria gigantea (accession 27-88*A), otherwise known as giant cane, which is one of three species of bamboo native to North America. Our specimen crests like a small wave against the Bussey Street wall, not far from the main entrance to Peters Hill. The dimensions of the plant are modest—the tallest stems, if straightened, measure little more than six feet high—but the species is known for forming expansive “canebrakes” that once swathed the floodplains of southeastern rivers, including the Mississippi River, with populations stretching as far north as Illinois. In the wild, the stems can reportedly reach more than thirty feet high, which, when multiplied across thousands of miasmic acres, was enough to inspire a severe brand of existential dread among early European travelers. Sometimes, too, canoe passage near the canebrakes included encounters with alligators and panthers (not to mention omnipresent clouds of mosquitoes), which is to say, the landscape inspired little affection.
Our accession of giant cane was collected along a small creek in south-central Tennessee. Rob Nicholson, the Arboretum’s assistant plant propagator at the time, dug divisions from this wild population during an eleven-day collecting trip, known as the 1987 Southeastern States Expedition, which followed two previous trips Nicholson had taken to the same region. The 1987 expedition began in the mountains of western Virginia and ended in northeastern Georgia. Along the way, he obtained significant collections of rare species, including longstalk holly (Ilex collina), two species of bush honeysuckle (Diervilla rivularis and D. sessilifolia), and Virginia spirea (Spiraea virginiana). In all four cases, Nicholson’s collection provided a substantial catalyst for the Arboretum’s conservation holdings of these species, which are now recognized, along with our collections of five other species, as part of the Center for Plant Conservation.
While giant cane, as a species, is in scant danger of extinction, canebrakes are considered critically endangered habitat, given that more than 98 percent of the ecosystem has been extirpated. Much of the loss can be explained by agricultural developments across the fertile bottomlands—a phenomenon supported by levees and other water-mitigation infrastructure—but researchers have also observed that, even now, habitat restoration in these river corridors tends to favor woodlands rather than canebrakes. The researchers point to a variety of factors to explain this, including feral hogs (which relish rooting for young cane shoots) and the need for regular wildfires. Yet I rather suspect that the gardener’s trembling at the mere mention of bamboo must be part of this story, the perennial phenomena where something once loathed (not to mention seemingly inexhaustible) needs to be loved.