4 minute read
The R . Henry Norweb Jr . Tree Allée is undergoing a redesign
Garden by Design
The R. Henry Norweb Jr. Tree Allée is undergoing a redesign to create a distinct space.
Annie Rzepka, Director of Arboretum Horticulture
Gardens are works of art — a composition of textures, colors and forms designed to elicit emotion — the landscape a canvas and the plants media. They are transient spaces in time, by season and year to year — bowing to forces from their external environment both below and above the soil. Gardeners work to control these external forces to extend the life of the intended design. Without them, these natural forces begin to dictate composition and form within the space and the garden transitions from a nurtured work of art to a work of nature — not necessarily a composition less beautiful, but a composition less designed and, in the realm of horticulture, less intended.
Upon reflecting on the gardens at the Arboretum over the last several years, it was obvious that nature played a greater hand in design than the gardeners had in some spaces. We have observed these changes throughout the Arboretum and notable redesigns have been focused in the mostly highly visited areas including Main Display, the Rhododendron Discovery Garden and Logsdon Pond. But behind the scenes, we have been planning a largescale redesign for the Tree Allee as well.
The R. Henry Norweb Jr. Tree Allee was established in 2013 and features the linear design of a traditional Allee, but with a twist. Rather than planting the same tree in repetition, five different trees were selected to add ecological diversity and horticultural perspective to the landscape. In the original design plan, one herbaceous species was selected for each type of tree and planted in an approximate 20-footby-20-foot section under each specimen. The perennial/ tree combinations were repeated all the way down the 370-footlong allee. But, as all gardeners know, sometimes conditions don’t always support the desired design. After more than five years interacting with the space, we decided it was time to start replacing the poor performing perennials and to reconsider the overall design of the space.
New garden design and redesign both take considerable thought and planning with the latter requiring our horticulturists to creatively invent opportunities which incorporate, preserve and enhance the aesthetics of existing structural design features and woody plant collections. After multiple design renditions, we decided to focus on the removal of all the existing perennial plant material. This decision allows us to address underlying soil conditions and a pervasive and relentless horsetail infestation, as well as fulfill our desire to create a feeling of continuity and fluidity for guests experiencing the allee garden while maintaining the original design intent. The redesign will enclose the allee so guests feel like they are in a distinct and
confined space using a mixed shrub hedge border. Additionally, the redesign elongates the view by extending plantings of forbs in drifts, rather than blocks, incorporating plant repetition in time rather than space, through a matrix of grasses. The new combination of perennial grasses, forbs and shrubs will also help extend seasonal interest. The annual zinnia and cosmos plantings are also included in the redesign plan to add a pop of color late season and deliver on what has become a fan favorite.
Initial improvements to the Tree Allee began in 2020 and will continue into Spring of 2023. Three of the five species of shrubs were planted last fall. Remaining perennial forbs were removed in May, and our garden team used cardboard to smother existing weeds. The patches of horsetail that evaded death by smothering are being hand treated one stem at a time with a water safe herbicide. We anticipate planting the remaining shrubs, grasses and perennial forbs this fall. Winter work will be focused on developing a comprehensive plan for the incorporation of bulbs with final touches occurring in spring 2023 depending on bulb availability and best planting practices as determined by each selected species.
MEET THE STAFF
Ann Rzepka is the Director of Arboretum Horticulture. She began her relationship with Holden Forests & Gardens as a volunteer in 1997 and was thrilled to be hired 10 years later as the horticulturist for the Myrtle S. Holden Wildflower Garden. Annie acted as the State Lead to collect seed and establish habitat for pollinators on behalf of the Pollinator Partnership and worked to help preserve rare and endangered plant species through her work with the Center for Plant Conservation.
