Making Cambridge Green Again

green cambridge

Ever seen one of those old 19th century photos of Cambridge? Back then, city streets were lined with huge elms and maples, their branches arching over the same paths we still walk today.

But by the early 20th century, archival photos show not a tree in sight along many of the city’s thoroughfares. Instead, the roadways of this industrializing area were lined with storefronts and tram cars, with factories looming in the distance.
Today, trees are a subject of renewed enthusiasm for the city, with residents and neighborhood groups interested in re-arboring Cambridge and keeping this urban forest healthy.cambridge trees

City Arbor-works

The vision of “a vigorous tree canopy throughout the whole city” is what motivates Florrie Wescoat, co-chair of Cambridge’s Committee on Public Planting. She and her colleagues know that trees are a critical part of the local ecology—they help combat the urban heat island effect and provide habitats for local wildlife, preserving a diversity of species.

green cambridgeBut Wescoat says that there are parts of the city where it’s hard to grow any trees at all due to dense building, traffic and other environmental conditions. The city’s approach is to improve conditions by minimizing factors like road salt and pollution. They work with both contractors and residents to maintain good health for new and existing trees and to choose hearty species that can survive in an urban environment. 

Cambridge’s City Arborist, David Lefcourt, explains that there are a number of scenarios that lead to the planting of new trees. Sometimes, the city is replacing old ones that were lost due to disease or weather damage. Other times, a construction project provides a planting opportunity. Lefcourt and his team will scout out potential planting sites, and often, residents request trees. A city initiative called the Back of Sidewalk Planting program lets eligible property owners request that the city plant a tree on private land within 20 feet of the sidewalk.

All of this amounts to a good deal of planting. In 2015, Lefcourt’s team planted 500 new trees throughout the city.

Finding a diverse collection of tree species that will thrive in their urban New England environment is a key part of Lefcourt’s job. It’s a lot to ask of a tree to put up with confined growing spaces, soil compaction, road salt, pollution from cars, heavy pedestrian and bike traffic, heat from the sidewalk and minimal biodiversity, so species resiliency is essential. And Lefcourt can’t stick with just a few winners—he aims for diversity of species to guard against massive losses due to pest or disease. Thinking ahead to warming climate conditions, he chooses some varieties from mid-Atlantic states that may have better longevity in Cambridge in the future. Still, native trees remain crucial for providing habitat and biodiversity of bird, insect and microfloral species. Lefcourt counts the few native types that typically do well in urban environments as an important part of the city’s tree portfolio.

New, city-planted trees are now a relatively familiar sight, but it’s still a challenge for those little guys to survive their first few years. It takes a community to cultivate an environment, and these trees are all of ours to steward. That’s why the city has a few programs in place designed to help maintain new plantings and encourage resident involvement.

Through the Junior Forester program, local children ages 5-13 can adopt and care for a newly planted tree in their neighborhood—even outfitting the tree with a special name tag—while learning about trees and their care. Elena Saporta, landscape architect and board member of Green Cambridge, a group of residents working on environmental and climate issues, says out that two city-planted trees appeared on her block at the same time, one with a Junior Forestry tag. “The one cared for by the kid really took off,” she cheers, emphasizing that even the youngest Cantabrigians can make the city greener. Water by Bike is another community-based city program, a five-year-old initiative that finds three interns with bike trailers toting 300-foot hoses that they attach to fire hydrants and use to water new trees.

Young street trees in the city get green “gator bags,” bladder bags at the base of the trunk that can be filled with a hose and slowly drip water to the tree. The bags now have tags explaining their purpose, and door tags and literature are distributed to neighborhoods when new plantings are made. The city’s Urban Forestry Division guarantees that all new plantings will have basic in-house maintenance for at least two years and that all city trees get pruned by contractors once every six years. The importance of “a supportive community that loves trees” can’t be overstated, says Lefcourt, nor can “anything residents can do to help young trees get off to a good start.”

cambridge trees

green cambridgeGrassroots Tree Stewardship

Longtime Cambridge resident and current Green Cambridge vice president John Pitkin takes a long view, putting a challenge to citizens. “If we really want to re-arbor Cambridge, there needs to be a cadre of citizens who think of themselves and act as tree stewards, people who roll up their sleeves and do the watering, planting, pruning and work with the city. The city can provide leadership and education, so citizens can be a part of it.”

Pitkin advocates for the big picture in all regards. “There’s a public perception that trees are like big potted plants—not true,” he says. “The tree is the entire tree, roots to tip of leaves. Trees are connected to one another in a kind of urban forest, a community of trees that sustain humans and other species.”

Pitkin’s view is shared by Cambridge Trees, a group within Green Cambridge that welcomes participants, volunteers, staff and donors to help with local tree-planting projects, primarily on private property. The initiative formed because, as organizer Susan Labandibar points out, “Trees need friends.”

“Cities and towns usually have an arborist or a tree warden, but it’s really not enough,” she says. “They’re constantly being asked to take down trees, plant new trees, manage invasive species and weather, road salt, aging trees. It’s endless.” As private citizens, Labandibar and her colleagues are excited to be “friends of the urban forest,” and they look for tree-related projects that need neighborly attention.

Cambridge Trees’ first project will be giving residents an opportunity to order small, native, bare-root trees that typically have a high success rate and can be planted by an amateur in their yard. Planting a tree is “kind of like having a baby,” Labandabar says. “It takes a lot of care.” She proposes that neighbors get together and establish a watering plan for city-planted trees, or even make a “tree plan” for the neighborhood.

Labandibar says it’s not enough to simply replace old trees. “The life of street trees is typically short. If we care about long-term tree stewardship, we have to care for our heritage forest,” she explains. She has her personal favorite oldie-but-goodie: the craggly Ancient Maple in Longfellow Park. It inspires her to wonder, “Why did these very old trees live so long?”

That level of engagement with and concern for our urban environment is what helps it thrive—and what makes it fun to share.

This story originally appeared in our May/June print edition, which is available for free at more than 200 drop spots throughout Cambridge (and just beyond its borders) or by subscription.