Tree on the move

by Jonathan Damery

December 3, 2018

Hemlock on the move

Tree on the move

Hemlock on the move

A large weeping hemlock (Tsuga canadensis forma pendula ‘Brookline’, 655-55*A) is transplanted into a new home at the Weld Hill Research Building. Photo by Andrew Gapinski.

Trees normally like to stay put. Some grow as colonial masses, pushing up new stems feet away from the original trunk, even covering a whole mountainside (as with the quaking aspen, Populus tremuloides)—all one plant, slowly spreading—yet it scarcely takes an experienced field botanist to know that tree locomotion is primarily the realm of whimsical literature. Only within the flip-book animation of words can trees amble on spindly roots and speak in sonorous tones. Yet trees do move about, even old ones, or at least they can with a little help. This was recently demonstrated by a weeping hemlock (Tsuga canadensis forma pendula ‘Brookline’, accession 655-66*A) that moved halfway across the Arboretum—roots, shoots, and all—assuming a position near the entrance to the Weld Hill Research Building.

The move was scarcely an elves-in-the-workshop surprise; rather it took considerable planning and horticultural talent. The hemlock had been growing near the Dana Greenhouses since 1967—claiming its most long-term position there in 1973. Over the ensuing decades, the plant slunk wide and draped low, forming a cavernous hideout beneath its branches, the kind of space that could entertain an industrious child for endless summer afternoons. The hemlock was exceptionally compact for its age—scarcely rising above five feet—yet it was perfectly proportioned for its landlocked position between the greenhouse fence and the adjacent driveway. Over the past year, however, Arboretum staff have begun to consider reconfiguring access to the Bonsai and Penjing Collection, located on the other side of the fence, and it became clear that the hemlock wedge would likely be reduced to a sliver, if not altogether removed. The tree would have to go.

Hemlock in transit—roots, soil, and all. Photo by Michael Dosmann.

So, before the tree pushed out new growth last spring, horticulturist Greg LaPlume began preparations for the move. He hand-spaded a trench beneath the dripline of the hemlock’s canopy, pruning roots to encourage a flush of new underground growth closer to the trunk. The trench was refilled, and in late October, Greg returned, with horticultural technologist Scott Phillips, and the men exhumed the trench (initially only one foot deep) and continued downward. Eventually, Greg and Scott could fit inside the trench, and they began curving beneath the plant, the branches overhead completely sheltering them from view. Many visitors at the Bonsai and Penjing Collection must have heard the scrape of spade on soil without seeing the two men working beneath the branches. Once the roots and soil were shaped into a rounded mass, about eight feet in diameter and three feet high, Greg and Scott swaddled the mass with burlap and laced everything tightly with an elaborate cat’s cradle of twine. The hemlock was then hoisted onto a trailer—an operation that required a powerful front-end loader borrowed from Harvard Landscape Services—and transplanted near the Weld Hill Research Building, where the pendulous branches are expected to cascade down the banked slope.

In some sense, however, the tree has an even longer history of movement. It arrived at the Dana Greenhouses in 1966 as a layer (caused when a branch touches the ground and sprouts new roots) from a tree in Brookline, Massachusetts, on the former property of Charles Sprague Sargent, founding director of the Arboretum. Sargent’s estate sprawled over pastoral hills near Jamaica Pond, and when the naturalist John Muir first visited in 1893, he described it as “the finest mansion and ground I ever saw. …trimmed with exquisite taste.” The hemlock was situated at the foot of a long veranda that opened beneath the house, where it seemed to burble across the surrounding lawn like a low fountain. Given that propagation by layering creates a genetically identical clone of the original plant, the move from Brookline could almost count as another peripatetic step. Sure, the plant didn’t move with its primary trunk, but does that matter? The initial roots were grown in the same Brookline soil; the central stem was formed there as well.

At the very least, the Sargent tree had rootloose tendencies. It was brought to the estate in 1871, transplanted from a population of dwarf hemlocks that were found growing wild in the Fishkill Mountains, near the Hudson River, in New York. The complicated backstory of how these seedlings entered cultivation, which Peter Del Tredici unspooled in his first-ever Arnoldia article (published in 1980), involves a veritable who’s who of early Arboretum names, including Horatio Hollis Hunnewell, whose support for the Arboretum is recognized with the name of the Arboretum’s administration building. It seems appropriate, therefore, to bring a representative of that early history to the landscape at Weld Hill. The building opened in 2011, and the surrounding beds are populated by many plants that have been collected on expeditions throughout China and North America over the past decade. Because this hemlock—or at least the genetic lineage, depending on how you split the needles—was collected before the Arboretum was even founded, it seems an elder statesman has returned the court. This time, too, the wanderer seems guaranteed to stay.

2 thoughts on “Tree on the move

  1. Flip-book animation of words, slunk wide and draped low, rootloose tendencies: thanks for more of your animated language!

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