and Choosing Replacement Trees and Shrubs for the Glencarlyn Library Garden
by Judy Funderburk & Elaine Mills, Extension Master Gardeners
Photos by Judy Funderburk, unless otherwise noted
How does one put into words the feelings of loss when two steadfast tree friends who stood as bookends towering over the Woodland/Shade, Native Plant, and Asian Gardens, are declared “unsafe?” Each of these carefully cultivated teaching gardens within the Glencarlyn Library Community Garden suddenly lost its shade as our two oldest trees were cut down to stumps within weeks of each other. Counting their rings, we estimate that each was planted 60+ years ago.
The Library Garden coordinators had been aware for years that the large red maple (Acer rubrum) near the Third Street entrance and the green ash tree (Fraxinus pennsylvanica) that provided shade for the patio had challenges. Rot was easy to see at the base of the maple, and the ash had dieback on some branches. Still, being told that each was considered a serious risk to those who walked through the Library Garden was hard to accept.
Photo by Anne Reed
After a spring storm brought down several limbs of the maple, Arlington County’s Parks and Recreation Department’s Natural Resources staffers for tree maintenance determined that it posed a danger to those who passed under its branches and that it needed to come down. A large crane was brought in and the tree was removed.
Four weeks later Master Gardener Paul Nuhn happened to lean against the trunk of our green ash tree and felt the bark give way. Thinking it had succumbed to the emerald ash borer,* even though the County had been treating the tree regularly for some years, we garden coordinators called in County Arborist Vincent Verweij. He quickly recognized that it was not ash borer damage, and diagnosed “vascular dieback” caused by root girdling. As the ash tree base and its root system grew larger each year, it came into contact with the brick patio. When the roots could no longer grow outward, they circled tightly around the trunk, cutting off the tree’s connection with its circulatory system. Water and nutrients were no longer being transported up through the tree’s xylem and the sugars created by photosynthesis were not flowing down through its phloem.
Verweij explained that ailing ash trees are known to drop limbs quickly, and so the County sprang into action, bringing in an even larger crane and removing the ash tree section by section until nothing was left but its beautifully encircled base.
The garden, of course, is not the same. The two trees provided dramatic year-round reminders of the seasons. In summer this included much appreciated shade for people and plants alike. These losses are very tangible, forcing all of us and all the plants adapted to their leafy coverage to adapt as best we can, while also reminding us that just as a garden goes through natural and inevitable changes, so must we.
Video by Judy Funderburk
In facing the changed environment of our gardens caused by the loss of these trees, our coordinator team met with Mr. Verweij in his capacity as urban forest manager to consider which native trees might be good replacements. After research and lengthy discussion, several species that are new to the garden have been selected as appropriate for the site.
The large red maple formerly at the 3rd Street entrance will be replaced by a post oak (Quercus stellata), a tree species native to the eastern and central United States. This member of the white oak group is slow-growing with a dense, oval crown that will eventually reach 40 to 50 feet in height. The USDA describes it as a “beautiful shade tree [that is] often used in urban forestry” due to its resistance to drought, fire, and disease. Post oak leaves have five deep lobes arranged in a cross-like shape. Brown, egg-shaped acorns appear from September to November, providing food for a variety of animals, including woodpeckers and blue jays. The tree also provides support to the caterpillar stage of the Imperial Moth and several Hairstreak and Duskywing butterfly species.
Photo © Stephanie Brundage
Photo © Elaine Mills
Photo © Alan Cressler
The ash tree that shaded the back patio of the garden will be replaced by a yellowwood tree and two American snowbell shrubs. Yellowwood (Cladrastis kentukea), a medium-sized species native to the southeastern U.S., is an excellent specimen or shade tree that eventually reaches 30–45 feet. It has smooth, beech-like bark and graceful branches with bright-green compound leaves that turn a delicate orange or yellow in the fall. Yellowwood has showy, foot-long spikes of fragrant white flowers from April to May, followed by yellow-brown seed pods in July and August. The tree provides nesting sites for songbirds as well as high-quality pollen and nectar for bees and other pollinators.
American snowbell (Styrax americanus) is a large shrub in the silverbells family that is native to the southeastern U.S. It grows 6 to 10 feet tall and wide with bell-like white flowers, reflexed petals, and dangling yellow stamens. Its sweet fragrance attracts bees, butterflies, and moths from April to May. We’re looking forward to having several fragrant plants blooming in our patio area in years to come.
*The emerald ash borer (Agrilus planipennis) is a destructive wood-boring pest of ash trees (Fraxinus spp.). Native to China, Mongolia, North Korea, South Korea, Japan, Taiwan, and the Russian Far East, the emerald ash borer beetle (EAB) was unknown in North America until its discovery in southeast Michigan in 2002. Today, EAB infestations have been detected in 36 states, including Virginia, Maryland and the District of Columbia.