NeighborWoods FAQs

Frequently Asked Questions About the NeighborWoods Program

•  How do you choose the appropriate height and/or type of tree to plant as a street tree?
• Why are there so few native tree species offered?
• How does the width of the planting strip affect the potential choice of street trees?
• How does the building setback, proximity to the road and/or sidewalks, and the proximity to other trees affect the type of tree chosen for planting?
• How do overhead power lines and underground utilities affect the choice of trees or their placement?
• Can I get free trees if I don't live in Olympia?

How do you choose the appropriate height and/or type of tree to plant as a street tree?

We begin with the premise that you are working as a partner with us to prevent improperly planted trees that are not appropriate for their sites, such as trees that are too tall planted under power lines or trees that get too large for narrow planting strips. A representative of the Urban Forestry Department will make an appointment to meet with you on your individual planting site after you have attended the NeighborWoods Basic Workshop. At the site visit, we evaluate the site and your preferences. We take into consideration as many of the potential strengths and limitations of the site as possible, constraints such as the width of the planting strip, building setbacks, proximity to the street and/or sidewalks, proximity to other trees and vegetation, the presence or absence of overhead power lines and underground utilities, and soil type and condition. We also work with your preferences for spring flowering, fall color, fruit for birds or no messy fruit at all!

We recommend, and offer through the NeighborWoods nursery, only single-trunked, deciduous trees for use as street trees. We have found most conifers to become far too large at maturity for street trees, their trunks and large roots outgrowing the limited space in most City rights-of-way. Their lower branches, if not trimmed, also impede both vehicular and pedestrian traffic and greatly reduce visibility for driver and pedestrian safety. The beauty and structural stability of a conifer are affected adversely by limbing up in a way that deciduous trees are not. Traffic safety and visibility are also why multiple-trunked trees or thick shrubbery in rights-of-way along streets are discouraged. back to top

Why are there so few native tree species offered?

Unfortunately, most of our Pacific Northwest native trees get far too large for street trees. The conifer species in particular want to be BIG forest trees and quickly outgrow most urban settings, as well as restricting visibility unless limbed up in an unattractive (and sometimes unsafe) way.

Many of the native deciduous species belong to the willow and poplar families, which we discourage planting in the City due to their aggressive root systems that seek out and have the potential to break sewer and water lines.

Of the remaining native deciduous species, there are several that are attractive, and we have been experimenting with them in street tree plantings. The results have been mixed: vine maple, preferring life in the shady understory of a forest, is extremely susceptible to unattractive and stressful scorching in hot summers, so must be sited where it gets protection from too much sun and heat. Pacific dogwood also prefers to be part of the forest rather than a loner and appears to be quite susceptible to pollution, heat, and other urban stresses. We have not had good success with this native species, although we will be testing a hybrid of this tree and the Eastern dogwood that has been successful in Vancouver, B.C. Big-leaf Maple handles urban stresses extremely well; its enormous size at maturity, however, limits its usefulness in an urban landscape. A few other species are limited by considerations such as short life span (red alder), difficulty of transplanting (madrone), site-specificity (Oregon ash), or extremely slow growth (Gary oak). We are trialing other native species as they become available in quantity through the nursery trade. back to top

How does the width of the planting strip affect the potential choice of street trees?

A tree that matures with a trunk too large for a narrow planting strip is much more likely to damage sidewalks, curbs, and/or streets, requiring costly repairs. Such damage to the trunk also ultimately leads to the death of the tree—and costly tree removal. So we fit the tree to the space: a tree of small stature in a narrow planting strip, a larger tree in a larger planting strip.

An important factor is the variety of tree: some trees are known for having aggressive surface roots that are damaging to streets and sidewalks, especially when constricted in a narrow planting strip. For instance, experience has shown that almost all flowering cherries have large aggressive root systems that can buckle a sidewalk even at a young age; note that we do not carry ornamental flowering cherries in our nursery inventory for that reason.

Soil conditions are yet another factor. Westside Olympia is built on a soil type called Alderwood that typically has an impenetrable hardpan just a few feet below the surface. Shallow soils like these cause tree roots to remain close to the surface, making them more likely to cause damage to sidewalks, curbs, and streets. back to top

How does the building setback, proximity to the road and/or sidewalks, and the proximity to other trees affect the type of tree chosen for planting?

We want to limit the potential for conflict or competition between tree branches and buildings, cars, pedestrians, and other trees. City specifications are for mature trees to be maintained at a height of 14 feet over a street or road for vehicular clearance and 8 feet over sidewalks for pedestrian clearance. Tree varieties are carefully chosen to have a size and/or branching structure that will cause the least conflict at maturity, and they are carefully located a prudent distance from buildings and other trees—it's not a good idea to have a tree growing into a building or other trees. back to top

How do overhead power lines and underground utilities affect the choice of trees or their placement?

Puget Sound Energy is required by law to provide for the safe transmission of power to their customers. In certain instances, this may require pruning trees to provide clearance for power lines. Often the degree and severity of such pruning on larger trees is damaging to their health and structural integrity. To ensure that our street trees remain healthy and structurally sound, under power lines we plant only those trees that mature to a shorter stature and thus require minimal, if any, pruning for clearance. Other overhead utility lines, such as cable, telephone, etc., do not require clearance pruning; however, we still recommend trees that fit below those lines in order to prevent damage and loss of service from tree-related incidents.

While most underground utilities are not directly affected by having trees planted over them, care must be taken not to cut or dig into such utilities while planting trees. The one exception to tree roots affecting underground utilities is the lateral sewer lines in older Olympia neighborhoods. These lateral sewer lines those leading from the sewer main in the street to the house—were built with sections of concrete or tile pipe that typically leak at seams. The water and nutrient leaks attract tree roots, which often grow into the sewer line, plugging and sometimes even breaking the older sewer lines. This is a significant problem, especially when poplars, willows, cottonwoods, or similar types of trees are planted anywhere near the lines. We are extremely careful in our tree selection and in the location of new trees in these older neighborhoods for this reason. NO tree should be planted near an older sewer lateral line, and we recommend that poplars, willows, cottonwoods and their relatives not be planted anywhere in older neighborhoods.

Underground utilities must be located before any tree planting activity is done. The Utilities Underground Location Center (UULC) is a free service, with a toll-free number: 1-800-424-5555. As part of your involvement in the NeighborWoods Program, we ask that you call the UULC after the site visit but before we deliver your trees, so that planting locations may be adjusted if necessary to avoid conflicts with underground utilities. back to top

Can I get free trees if I don't live in Olympia?

Unfortunately, the free trees and individual guidance provided by the NeighborWoods Program are available only to residents within the city limits of Olympia. Check with your local government for similar programs in your city or county. Another low-cost tree resource to investigate is the windbreak program sponsored by the Natural Resource Conservation Service (NRCS). The local NRCS Service Center is located at 1835 Black Lake Boulevard SW, Suite B, Olympia, WA 98512-5715, or call 360.704.7740. Thurston Conservation District sells conservation-grade native plants, including trees. More information is available on the TCD website or by calling 360.754.3588.

Free workshops and seminars sponsored by the NeighborWoods Program are, however, open to everyone, regardless of residence, subject to available space. Please call the NeighborWoods Hotline at 360.753.4444, Extension 3810 to check if the workshop or seminar you wish to attend has space available. back to top