HomeMy WebLinkAbout2019-Lexington Tree Committee Recommendations for Tree Planting Lexington Tree Committee Recommendations for Tree Planting
A collaborative effort of the Tree Committee and Department of Public Works
Approved December 12,2019
The intent of this document is to promote a set of best practices for the town tree-planting program,
and for the monitoring,maintenance and reporting of those trees planted. In any situation
possible,there is a preference for planting large native shade trees.
TREE SITING
• The Tree Warden/ Forestry Division is responsible for
o maintaining and updating a list of potential planting sites,including locations where
trees have been removed;
o identifying planting locations for each season's planting program;
o visiting sites and managing the setback planting program;
o managing contractors engaged to plant trees;
o maintaining a list of planting sites to include size, species,planting date,etc.to be
updated and shared with the Tree Committee after the spring/fall plantings and
integrated into the Tree Inventory.
• The Tree Warden/Forestry Division shall manage relations with homeowners for both public
trees planted in the right of way and for trees planted in the setbacks of private property. This
will include
o Responding to homeowner requests for setback trees to be planted on their property.
o Notifying homeowners that a tree will be planted in the public right of way in front of
their homes. Homeowners have significant input,with ultimate authority for trees in
the public right of way resting with the Tree Warden.
• There shall be a bias toward planting even if the physical site is less than ideal. Where there is a
need for more shade and planting conditions are not ideal but are feasible,there shall be a
willingness to experiment,including the following considerations:
o New or replacement trees shall be planted at or near the site of removed trees.
o The minimum size planting well will be 3 feet by 6 feet, or 16 square feet with a
minimum width of 3 feet. Tree wells less than this may be evaluated on a site-by-site
basis.
o The tree well should be as wide as possible,so long as minimal ADA requirements for
the adjoining sidewalk are met. Where possible,pavement shall be cut to extend the
size of the tree well. Tree grates or other technologies can be used to provide walking
surfaces while allowing access for snow removal.
o Trees of appropriate size and species may be planted under wires.
o Minimum distances of the planting site from other trees,underground utilities,fire
hydrants, driveways,parking meters,utility poles,etc. should follow industry standards.
Less than ideal distances will be evaluated on a site-by- site basis. See Appendix for
guidelines.
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LOCATION PREPARATION
• Soil removed from the planting hole shall be replaced with good quality topsoil similar in
texture to the existing soil.
• If a sidewalk is being replaced, sand-based structural soil under sidewalk should be considered.
• The Tree Warden/Forestry Division will explore and may use appropriate technology (tree
grates, etc.) as warranted to prevent or mitigate soil compaction in heavily traveled areas.
SPECIES and ORDERING
• The Tree Warden/ Forestry Division shall arrange for the planting of trees species from the
master list provided by the Tree Committee.
o Trees maybe ordered by the Town or by the contractor who will plant them.
o Bare root trees are preferred when trees can be planted quickly(within one week) after
delivery.
o Contractors shall guarantee the trees' survival for 1 year.
• Risk shall be mitigated for pest host trees or those in decline due to climate change,with
consideration for the existing insect or pest situation in surrounding communities.
o No sugar maples shall be planted
o No ash trees (EAB hosts) shall be planted
o ALB host trees shall be planted only when there is a compelling reason to do so, and
shall be limited to a maximum of 20% of the trees planted in a given year.
o Monocultures shall be avoided by planting 2 or 3 species in an area,unless a particular
visual effect is necessary.
WATERING and CARE
• Watering shall be a major focus of the tree planting process,for up to 5 years.
o Newly planted trees shall be watered for a minimum of 2 years, and longer in drought
conditions.
•The Tree Warden /Forestry Division shall ensure that the planting contractor,town or
residents are assigned responsibility for watering trees.
• It is recommended that salt-laden snow should not be piled on or near trees.
MONITORING
• The Tree Warden/Forestry Division shall monitor recently (within prior 5 years) planted trees
and takes action if required (watering,pruning suckers and low branches,removing stakes,
replacement, etc.)
SURVIVAL RATES AND REPORTING
• Archival records shall be kept of locations and species of trees planted, removed and replanted,
and of survival rates.
• This information shall be reported on a regular basis to the Tree Committee,and summary
statistics will be included in the Town's Annual Report.
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APPENDIX: TREE PLANTING GUIDELINES
Unless otherwise specified,numbers given are minimum distances from tree center:
Tree pit size at least 3' x 6' or 16 square feet with
minimum width of 3'
Distance from curb edge,where street has curb 30"
Distance from adjacent trees 15'-40',varies with species
Distance from street intersections 20'
Distance from driveways 5'
Distance from fire hydrants 5'
Distance from underground utility lines 5'
Distance from gas or water valve 5'
Height of mature trees under utility lines 30'maximum
Distance from street lights 10',varies with species
Distance from utility poles 5'
Distance from stop sign 20'
Distance from traffic signs Depends on sightline requirements
Distance to opposite obstructions 5'
Suggested distance from parking meters 3'
Passage for ADA considerations 3'wide sidewalk
Passage for sidewalk plows 5'wide sidewalk
Less than ideal distances will be evaluated on a site-by-site basis.
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