Trees on our recommended list represent varieties that have shown hardiness to our Portland, Maine climate, display favorable characteristics and are generally available in the nursery trade. ‘Co-Op’ Nurseries offer a wide selection of shade and ornamental trees, including trees native to New England along with interesting non-native ‘exotics’. Trees with * are readily available and especially recommended.
Trees are grouped into the following categories: Small, Medium & Large and by site use: "Street trees" (ST) which are trees recommend for planting between the sidewalk and street, or along street lines due to desired characteristics such as branching height, shape and hardiness to grow in urban conditions. Street-trees tend to include more ‘shade trees’ that are grown for shade vs. ornamental qualities. "Lawn trees" (L) are ‘setback planted’ away from the esplanade or street on the lawn area. They can be multi-stemmed or lower branched than the street-trees and may be less tolerant of urban conditions. "Lawn trees" include: ‘shade’, ‘ornamental’, ‘conifers’ along with “fruit & nut” trees. Lawn trees can be smaller in size then ‘Street trees’.
It is important to match the desired characteristics of the tree to the site where the tree is intended to grow. ‘Plant the right tree - in the right place’. Shade, screening, ornamental qualities such as flowers, fruit, or interesting bark, how big will the tree grow and where will it grow best? What are the site conditions - wet or dry, sun or shade? Trees need room to grow, picture the mature tree size growing in the location you plant to plant the new tree. See updated USDA Plant Hardiness Map: http://planthardiness.ars.usda.gov/PHZMWeb/#
Planting Site Guidelines
Trees planted in sidewalk ‘treewells’ have a minimum width of 3.5’ / leaving 3’ for wheelchair and pedestrian travelway. In restricted areas and under utility lines we recommend ‘setback’ tree planting behind the sidewalk. Trees must be planted 10’ from intersections, driveways, walks, utility poles and fire hydrants. (This is to avoid future problems)
Tree Size Recommendations; Street-trees: 1.75” - 2.0"
caliper, (thickness of the trunk at the base) and #5 gal pot size - 2"
for lawn planting. Maximum sizes - 2.5" caliper for shade and ornamental
trees and 6’ Height for conifers.