Municipal Street Tree Selection

Street trees play a vital role in shaping the character and beauty of a town. They provide seasonal interest, create a welcoming atmosphere, and offer countless environmental and social benefits. The right trees, thoughtfully selected and strategically planted, can enhance both the aesthetics and functionality of urban spaces.

Businesses, for instance, benefit from the cooling shade and inviting ambiance that street trees provide, which can improve customer experiences and encourage foot traffic. Trees contribute character, atmosphere, and comfort for outdoor seating and dining. However, improper tree selection and placement often lead to issues that shorten a tree's lifespan and detract from its value.

Challenges of Street Tree Placement

Most street trees face a host of challenges, many of which stem from their urban environment. Vehicle damage, for example, is a common cause of decline. Low-hanging branches can be broken by passing trucks, while parked cars often cause bark damage from opening doors. Proper spacing between trees and planting them in areas that accommodate parking are critical steps in reducing such risks.

Some species are notorious for causing infrastructure problems, such as lifting sidewalks and breaking curbs. In some cases, trees should be planted on the other side of the walkway to avoid such issues. Narrow grass strips, often used in these areas, are challenging to maintain and waste water as irrigation runoff floods sidewalks and streets. Grass strips can be aesthetically pleasing if widened to six feet or more where space allows.

Additionally, the type of litter produced by a tree—such as fruit, acorns, or seed pods—should always be considered when selecting a species. Road salt, drought, and poor air quality further contribute to the stress on urban trees.

The Importance of Expert Tree Selection

Tree selection should go beyond mere aesthetics. Understanding a tree’s genetics and growth characteristics is essential. Professionals can assess mature height and width, canopy shape, seasonal interest, and potential maintenance challenges. For example, ash trees have suffered catastrophic losses due to the emerald ash borer, and ornamental pear trees, once widely planted, have proven short-lived and structurally weak. Kousa Dogwood or Rutgers Dogwood hybrids are excellent, hardy flowering substitutes. Norway maples, once considered ideal street trees, are now plagued by verticillium wilt, declining rapidly, and are listed as invasive species. Alternatives such as Yellowwood and Golden raintree are more sustainable choices.

Tree professionals don’t have a crystal ball, but their expertise in assessing long-term risks and benefits is invaluable. It’s troubling to still see towns planting ornamental pears, even when improved varieties are available. Municipalities should prioritize diversity in their tree selection to reduce vulnerability to pests, diseases, and environmental stressors. Avoid planting the same tree species throughout a town; mixing species ensures resilience. If one tree succumbs to disease or infestation, the impact on the urban canopy is minimized.

A Collaborative Approach

Choosing street trees and their locations is a long-term commitment that requires careful planning. Municipalities would benefit greatly from assembling a team of experts, including a nurseryman, landscape architect, licensed tree expert, and horticulturist. This team could create a diverse and regionally appropriate tree palette tailored to the town’s needs. Such an investment pays off over time, ensuring healthier, longer-lasting trees that require less maintenance.

Comprehensive planting standards should be developed to guide tree selection not only for streets but also for parks, sports fields, public spaces, dog parks, greenways, detention basins, and wildlife habitats. These standards can also serve as a benchmark for commercial and residential developments, promoting sustainable and functional urban landscapes.

Some Good Street Tree Performers

Here is a short list of trees that perform well in urban environments. Always consult a tree professional to ensure the selected species are appropriate for the specific space and location:

Ginkgo (Ginkgo biloba)
Lacebark Elm (Ulmus parvifolia)
Bloodgood Sycamore (Platanus acerifolia)
Kentucky Coffee Tree (Gymnocladus dioicus)
Kwanzan Cherry (Prunus ‘Kwanzan’)
Yellowwood (Cladrastis kentukea)
Goldenraintree (Koelreuteria paniculata)
Southern Magnolia (Magnolia grandiflora)
Fastigiate Hornbeam (Carpinus betulus)
Rutgers Dogwood Hybrids and Kousa Dogwood (Cornus)
Hedge Maple (Acer campestre)
Redbud (Cercis)
Shademaster Honeylocust (Gleditsia triacanthos var. inermis)

Funding Tree Planting

Many towns have established “Tree Fund” ordinances. When developers’ clear trees from a plot of land for residential or commercial development, they should pay for each healthy tree removed. If space is unavailable for replacement on-site, trees can be planted elsewhere on public property in town, or the funds can be allocated for tree maintenance.

There are also grant opportunities available for urban forestry projects. If your town does not have a tree fund ordinance, research towns that do to understand the benefits and how to implement such a program.