COBI_CLimateReadyTrees copyClimate change is expected to result in changes in dominant vegetation on Bainbridge Island, decreased
tree growth, increased fire risk for summer water stress, and changes in pest distribution and type of pest.
MAINTAINING A HEALTHY, MATURE TREE CANOPY IN THE URBAN AREAS OF OUR ISLAND REQUIRES THOUGHTFUL
PLANNING, A MIX OF DIVERSE SPECIES AND A COMMITMENT TO CONTINUING CARE.
The City of Bainbridge Island has compiled a set of Best Management Practices, or “BMPs”, to help guide
homeowners on the selection, installation, and care of trees in our changing urban environment.
SELECTING & CARING FOR CLIMATEREADY TREES
on Bainbridge Island
SPECIES SELECTION BMPS
Trees in urban areas have a higher
baseline of stress due to soil composition,
soil volume and water limitations, air
pollution, and inadvertent damage.
Climate change-ready species are
trees that possess attributes that
increase resiliency to drought, air
pollution, temperature swings, poor
soils and other environmental factors.
These species (or subspecies) should
be prioritized when planting to
limit additional stress on city trees.
• Choose a tree with a mature size
that is an appropriate size for the
space (i.e., small mature trees for
small spaces, larger mature trees
for larger spaces)
• Maintain diversity by following
the 10-20-30 guide for your
neighborhood: limit to 10% of
the same tree species, 20% of
the same genus and 30% of the
same family in an area
• Use a minimum of 50% drought
resistant species in the landscape
and consider native species first
(see planting list)
PLANTING BMPS
Trees that aren’t properly planted can
decline in health over time, and result
in extra care costs, reducing the
chance of long-term survival.
• Plant in the Fall for better
establishment
• Provide a 3–6" layer of mulch
in a “donut” shape
• Remove outer “circling” roots in
potted trees to encourage root
growth outwards from the stem
• Ensure root flare is exposed
when planting (as shown in
the figure below)
CONTINUING CARE BMPS
Trees in more urban settings—such as
front yard trees, street trees and
parking lot trees—require more
supplementary care and pruning than
those in forested areas.
• Maintain 3–6" of mulch extended
to the dripline of the tree
• Structurally prune young trees in
exposed areas
• Contact an arborist if you see
significant signs of change (insect
damage, large dead branches,
browning)
• Use supplemental watering during
periods of summer drought
RIGHT WRONGRoot Flare Root Flare
WHAT TO AVOID
These trees are not currently considered climate-ready due to pest and diseases
issues, or invasive tendencies. This list is subject to change based on scientific
research and changing pest forecasts.
• All “true ash” species (Fraxinus spp.)
• White-barked birches such as paper birch (Betula papyrifera) and
Himalayan birch (Betula jacquemontii)
• Tree of heaven (Ailanthus altissima)