3 minute read
Greenkeeper's Update - June 2020
By Tim Kennelly, CGCS, Head Greenkeeper
As you know, the Club has been working diligently on the Lifestyle Facilities Master Plan and has hosted numerous focus groups and Town Hall Meetings this spring. Throughout the process, Club leadership has made it very clear that we are committed to preserving and protecting the American Elm trees between the clubhouse and adjacent putting green. In early February, Wetland Studies and Solutions, Inc. (WSSI) was hired to provide an assessment of the trees and determine their suitability through the proposed renovations and clubhouse expansions. We were recommended to WSSI by Carroll Tree Service, who has cared for our existing Elm trees for numerous years and has a working relationship with their Senior Urban Forester Chris Cowles and Certified Arborist Cene Ketcham. They have worked together on numerous tree preservation projects starting at Johns Hopkins University and recently completed a successful tree restoration project on the North Lawn at The White House. Also, Carroll Tree completed the iconic Elm tree work in Washington, DC with the completion of the Lincoln Memorial Reflecting Pool Revitalization Project. They have completed their findings and the report and recommendations have been submitted to leadership for review.
Here is a summary of the Tree Inventory and GPR Root Investigation Study Report:
The trees were found to be in generally good health, and roots were mapped at various depths around each tree, under the bluestone, and in the grass outside the Tap Room. Though root density varied between the trees, most were found to have good density, primarily in the upper 12” range. There was a surprising quantity of deep roots detected under the existing bluestone patio, which will likely need to be verified as we are determining the location for footers, etc. Mr. Cowles and his team are confident that with their recommendations, the preservation of these trees should be possible throughout construction and for the foreseeable future, within the limits enumerated in the GPR report.
The Club is committed to the preservation of the American Elm trees at the clubhouse and regardless of how the Master Plan timeline is affected by COVID-19, there are some proactive and immediate steps that should be taken to improve the overall health and vigor of the trees.
Questions have been asked, but unfortunately planting any type of ground covers in the mulch area to improve aesthetics or prevent the washing of the mulch during and after storms is not an option since additional plantings will compete for available water and nutrients of the existing elm trees. Our team will be placing stone in between the trees as step-ways from the clubhouse to the putting green areas.
As always, please feel free to contact me or Cathy Wagner if you have any questions or concerns regarding this work. ◆
Club leadership approved the following measures while the courses were closed:
Increase Root Density with Mulch Layer
Converting the area under the Elm trees to mulch from the edge of the brick walkway to a minimum of 20’ beyond the tree trunks. This mulch layer will increase root density and bolster overall tree health in preparation for construction and potential root loss. As part of the overall Elm Preservation Plan, this mulch will be kept in place for the natural life of the trees.
Install Drip Irrigation
Tree and grass plants have vastly different water and irrigation requirements. Our team will install drip irrigation underneath the entire mulch panel to apply water as needed to the CRZ (Critical Root Zone).
Increase Drainage with Vertical Mulching
This method utilizes our team, along with Carroll Tree, to excavate small diameter (2-3”) vertical holes with an air tool in a selected pattern to fracture, de-compact, and blend the different soil types identified in the WSSI report. The holes will be backfilled with a special blend of biochar and compost to increase drainage, while improving aeration for the trees' roots to thrive.
Enrich the Soil
In addition to mulching and watering, Carroll Tree will be injecting biostmulant directly in the soil as part of our overall Stress Reduction Measures to improve tree and soil health. This formulation of beneficial micronutrients and rhizosphere bacteria work with microorganisms already present in the soil to facilitate the uptake of nutrients. These materials have been very effective for our American Elm trees that have experienced significant stress in the past.
