Attachment_10,_Shaw_-_Elm_Tree_Ring_Recommendation_8.7.18.pdf

The Growing tree 369 Stafford Street

Cherry Valley, MA 01611-3352

(508) 799-3953

August 7, 2018

Friends of the Public Garden 69 Beacon Street Boston, MA 02108 ATTN: Bob Mulcahy

RE: Shaw 54th Memorial – Report on Elm Growth and Tree Ring Expansion

The elm trees at the Shaw memorial are in good health. These trees are old trees and their basal growth is slowed by age but they do grow annually, maybe the width of a line on an LP record.

However, old trees produce more bark than wood and the annual amount of bark growth is unknown. The old rings are no longer supporting the health of the tree. During this construction project it is necessary to retrofit the steel ring surrounding the trees on the brick viewing area. I am advising a 25 year clearance for growth of this important living vascular tissue. Using a similar recommendation, as the 1981 Frost and Higgins report (see attached), the trees will need a minimum of 3 inches but, no more than 3.25 inches of clearance from all outer bark surfaces. Because the trees are not uniform circles it will call for skillful tradesman to customize and scribe the irregularities of nature. The old ring should be removed with patience and care. As per the Frost and Higgins report it may not be possible to remove steel in areas. If this situation is encountered the recommendation will be to remove/replace brick and not disturb tree, unless directed by Reviewing Arborist. The new ring shall be 1/8” x 5” steel plate. To prevent trip hazards on newly open area and debris from entering the tree well, a half inch square welded wire cloth, 11g, should be installed between the new ring and the tree’s rough corky bark. This wire cloth can be cut and fitted in small three foot long sections (or smaller) and shall be fitting in same manner as the Frost and Higgins detail (see attached image). All material shall be painted black. An arborist shall supervise this and all work with direct impact on these trees.

Norm Helie Arborist, Plant & Soil Science

Attached:

• 1981 elm related correspondence between Ann Beha Associates, Arnold Arboretum, Friends of the Public Garden, Frost and Higgins.

• Present day images of elms and brick plaza bmulcahy Rectangle bmulcahy Rectangle

Rings shall be 3” from the edge of the tree following the outer bark surface. Some arcs of the steel will able to be uniform but other will have to be scribed to allow for irregularities of the tree growth.

Without maintenance records post work conducted in early 1980’s it is difficult to determine if tree rings were positioned in areas that currently abut bricks. Note cuts on bricks to fit around tree or are rings bur-ied.

Detail of wire cloth from the

1981 Frost and Higgins report.

Wire cloth has been pushed in over the subsequent years.

Steel I-Beam and elm. Extreme care must be taken when working in and around these trees. All work under direct supervision of a Arborist

All excess construction materi-al or trash shall be removed from vault area

Location of both elms when looking into vault under plaza.