Approved Street Trees

Select the tabs below to find the approved trees for street use, along with their pruning, spacing, and shade calculation details. In addition, check the Prohibited Trees tab to find out which trees cannot be used as street trees. For other street tree information, go to the following links:

  1. Small Trees
  2. Medium Trees
  3. Large Trees
  4. Prohibited Trees

20-Foot Crown Diameter Canopy Trees

  • Crape Myrtle (Lagerstroemia indica)
  • Crimson Spire Oak (Quercus x 'Crimschmidt')
  • Easter Redbud (Cercis Canadensis)
  • Flowering Plum (Prunus cerasifera)
  • Lavalle Hawthorn (Crataegus x lavallei)
  • Musahsino Zelkova (Zelkova serrate 'Musashino')
  • Nyssa sylvatica
  • Prairie Fire Crabapple (Malus 'Prairiefire')
  • Scarlet Sentinel Maple (Acer rubrum 'Scarsen')
  • Shumard Red Oak (Quercus shumardii)
  • Sunset Maple (Acer truncatum 'Norwegian')

Spacing, Sidewalk Cuts, Shading Calculations

  • Spacing: At least 20 feet apart
  • Sidewalk Cuts: Equal to at least 4 by 4 feet
  • Shading Calculation: +/- 300 square feet

Pruning Requirements

Prune all trees to provide at least 8 feet of clearance above sidewalks and 12 feet above street roadway surfaces.

Priority List of Trees to Retain

In order of priority, these trees are to be retained during development:

  • Ponderosa Pine
  • Incense Cedar
  • Sugar Pine
  • Douglas Fir
  • Redwood
  • Black Oak
  • White Oak
  • Pacific madrone
  • Bigleaf Maple (Riparian only)
  • Oregon Ash (Riparian only)
  • Cottonwood (Riparian only)

Trees Recommended for Placement Under Power Lines

Small Trees - small or narrow trees (under 25 feet, less than 20 feet wide) may be spread at any interval 20 feet apart or greater. Sidewalk cuts equal to 4 by 4 feet or larger.

  • Eastern redbud (cercis canadensis)
  • Flame maple (acer ginnala)
  • Kousa dogwood (cornus kousa)
  • Thundercloud plum (prunus cerasifera "thundercloud")

Not Recommended for use as Street Trees

The following tree species are not recommended for use as street trees. The reasons are noted for each species. If the problems are satisfactorily met and accepted by the owner and noted on the site plan, these trees may be planted.

Not Recommended as Street Trees

Problems related to trees not recommended as street trees.
Tree / Species
Problems / Considerations
Big Maple Leaf - Acer macrophyllum
Roots cause injury to sewers and pavement
Birches - Betula spp
Aphids, low branching, invasive roots, injury to sewers, pavements
Flowering Pear (Pyrus calleryana) New cultivars have caused this "seedless" pear to start producing fruit. It has become an invasive species in several states.
Conifers needles, low branching
Fruit trees
Hawthorns - Crataegus spp
Insects and disease prone, aphids
Nut trees
Red Alder - Alnus rubra
Short lived, brittle, favorite of the tent caterpillars
Silk Tree - Albizzia julibrissin
Litter, aggressive roots
Sycamore - Platanus spp
London plane; vigorous roots, damage to sidewalks, sewers, serious anthracnose disease
Tree of Heaven - Ailanthus
Short lived, invasive roots