It’s a Friday afternoon and Vincent Verweij is leading me into the woods. Not the dark and forbidding forest of a fantasy novel, but the airy, picturesque woods near Bon Air Rose Garden and Bluemont Park in Arlington. As we walk across the grass toward Four Mile Run, oak, sycamore and other trees tower over us, their shadows lengthening in the late-day sun.
We stop at a scraggly patch of land just under an acre in size, close to the stream. In contrast to the manicured rose garden nearby, this space has a wilder feel, with wavy tall grass and a profusion of saplings. Verweij, the county’s urban forestry manager, rattles off a few of the nearly 20 species growing around us: black locust, sycamore, black gum, hornbeam.
“This area used to have a bathroom, an accessory building and a basketball court,” he says. “It all flooded out in 2019. That’s the negative part. But then we saw an opportunity. A private real estate company wanted to do something good and donated some money to remediate the soil here. We replanted it with all native trees.”
Seizing opportunities to plant and save local trees is the central focus of Verweij’s job. Industrialization and development, along with wildfires, major storms and invasive species, have led to concerning levels of tree canopy loss, both nationally and globally. With new construction happening in seemingly every corner of Arlington, McLean and Falls Church, the local landscape faces the same pressures close to home.
In Arlington, trees are everywhere and nowhere, all at once. Some 755,000 of them line our streets and creeks, and shade our office buildings, schools and homes, according to county data. Large specimen trees serve as home base for kids playing tag or hide-and-seek. Hikers enjoy the lush forests of places like Donaldson Run and Potomac Overlook Regional Park.
At the same time, many locals lament the dearth of street trees on certain residential blocks. Constant development and redevelopment have often meant the loss of mature trees, either through outright removal or damage to root systems caused by construction, flooding or stormwater runoff.
Pests have also taken a toll. The spotted lanternfly is just one invasive bug that has chewed up trees in the area, particularly the non-native tree of heaven. Other invasive insects, including multiple species of flathead borers—the emerald ash borer is probably the most infamous—feast on a wide range of native Virginia flora.
When old-growth trees die or are removed and replaced with younger trees, it takes years or decades to recoup the benefits that mature trees provide, including shade and cooling, stormwater retention, wildlife habitat and sequestering carbon from the atmosphere. “Arlington is doing some good things with its tree canopy,” says Julie Udani, principal of Greener Gardens Landscape Design, “but by the very nature of the community, some bad things are happening, too. It is a very urban environment. The problem is that trees require space. The roots need soil, and the canopy you see above, it pretty much needs that same space below for the roots.” Constricting the root system means that the average street tree’s lifespan might be only five to seven years, she says.
It’s a global problem. According to research from the World Resources Institute, tree canopy loss has accelerated worldwide in recent years, from 13.4 million hectares (Mha) lost in 2001 to 28.3 Mha in 2023. (A hectare is approximately 2.5 acres.) Here in the U.S., the nonprofit Global Forest Watch reports that 47.9 Mha of tree cover disappeared between 2001 and 2023, representing a 17% decrease in a mere quarter century.
Major U.S. cities are fighting to maintain a healthy tree canopy: New York City’s total tree coverage is 29%. In the city of Los Angeles, it’s 25%.
Arlington’s numbers (because it’s less urban) are notably better, although not yet up to the levels that the county—and many private citizens—would prefer. A countywide tree study released in November 2024 indicates that Arlington’s present-day tree canopy is 35.2%, up from 31.7% in 2014 and 33.3% in 2018. The study was conducted after the county in 2023 adopted a forestry and natural resources plan that establishes a goal of 40% tree canopy coverage by 2035, with the majority of those trees (70%) being regionally native species.
Neighboring jurisdictions enjoy even higher percentages of tree cover, by virtue of having more open land and larger lots. The City of Falls Church has 49% tree cover, while Fairfax County has about 55%. The District of Columbia has a canopy similar to Arlington’s, calculated at 37%.
Although Arlington’s tree census has been moving in a positive direction, it’s uneven. Verweij points out that a percentage alone can’t convey the number and types of trees on every block, or whether that block has sufficient or desirable foliage. He and his team are regularly out in the field, surveying trees and taking note of the blank spaces.
Essential to this work is a detailed map, available on the county website, that illustrates the county’s tree canopy concentrations in a range of greens. “You can actually zoom in and see where trees have grown, and where trees have been lost,” he says. “There are a couple of neighborhoods where there’s been a little bit more loss.”
Arlington is becoming more urbanized, yet it still has great potential to accommodate more trees, according to a 2023 countywide urban forest assessment prepared by Mary Glass, director of the Arlington Tree Connection, a citizen tree advocacy group, in conjunction with the Green Infrastructure Center in Charlottesville, Virginia. The analysis identified space for 132,660 new trees around the county, including 5,315 on school grounds, more than 10,000 in parks, 44,202 along streets and more than 73,000 on private property.
Working with a team of foresters and tree crews, Verweij engages with private citizens, community groups, developers and neighboring jurisdictions to prune or remove diseased or hazardous trees, plan tree restoration efforts and review building permits.
In Arlington, new construction projects—particularly those of 2,500 square feet or more—require landscape plans that include tree planting and protection measures. That’s where a volunteer army of tree lovers comes in.
Nora Palmatier knows that seeing the forest for the trees is not just a metaphor. Protecting trees involves work on multiple fronts, she says, and an eye on the bigger picture. Palmatier presides over a volunteer group called Tree Stewards of Arlington and Alexandria, which has been around since 2001. Its members undergo light forestry training and participate in activities such as pruning and mulching trees, leading neighborhood walks and doing public outreach about tree care.
Palmatier says the county does a good job updating and assessing tree canopy maps to identify areas in need of attention. Her group hopes to convince more homeowners to protect existing trees on their properties—and to plant new ones, choosing native species whenever possible.
“I was just with a friend from Dominion Hills, and she was pointing out how she used to be able to take her dog for a walk, and it was all shaded on the sidewalks. Now, it’s not. People aren’t replacing the big trees [when they lose them],” she says. Doing so can be expensive.
“That’s not something the county can control,” she adds. “They can encourage it, and we can lead tree walks and talk about it. But private [property owners] have to say, ‘I want more trees.’ ”
Equally important are the kinds of new trees homeowners choose to plant. When recommending trees to her landscape clients, Udani gives what she calls her “dogwood talk.” Many local nurseries sell two kinds of flowering dogwoods: One is a native dogwood, Cornus florida, the Virginia state tree; the other is Cornus kousa, a non-native dogwood from Japan.
“Our native dogwood supports more than 100 different species of birds and insects,” Udani says. “The kousa dogwood supports zero. The native dogwood has evolved with our migrating birds, so in the fall, just as the birds are getting ready to set off on their migrations, that’s when the native dogwood berries are ripe. In the spring, it starts to flower when the bees are coming out. The Japanese trees don’t bloom or berry at the right time. It’s like wax fruit in your kitchen. It’s pretty, but you can’t eat it.”
Removing invasive plants, such as non-native ivy that chokes out native trees, is a major focus for Plant NOVA Trees, a joint initiative of local nurseries, governments and citizens that advocates planting native trees to protect biodiversity. (For a list of recommended species, click here). Protecting existing trees is also essential, says coordinator Margaret Fisher.
“Even though it is very important to add more trees in areas that are really urbanized or in commercial districts,” preservation is just as critical, Fisher says. “We’re just spinning our wheels if we’re losing grownup adult trees faster that we are planting little baby trees.”
Sometimes tree-loving citizens take matters into their own hands. In the Aurora Highlands neighborhood where I live, my neighbor Mark noticed a while back that our block didn’t have many trees planted along the street. He began acquiring trees from various sources—usually new construction projects that planned to remove or destroy them (although I admit to not knowing the provenance of all of them)—which he then transplanted himself.
About six years ago, he installed a rescued oak tree in the two-foot plot of grass between the sidewalk and the curb in front of my house. When I expressed concern that the oak would eventually grow too big for the space, his response was pragmatic: “You won’t have to worry about that for a long time. In the meantime, you have a tree.” The county has since kept that tree pruned and cared for, along with all the other street trees Mark has rescued and planted.
Elsewhere in Arlington, tree stewards are getting creative and finding new ways to promote greening beyond the usual environmental benefits. A new project at Drew Elementary School is a case in point. Soon, the school will be home to an urban orchard, thanks to Mary Glass and the Arlington Tree Connection.
After learning that many residents of Arlington’s Green Valley neighborhood used to keep fruit trees, Glass rallied community organizers to secure a grant to plant an orchard at the school. Once installed, this grove of at least 18 fruit trees—possibly including apple, fig and pawpaw trees, along with some bushes—will provide shade, habitat and learning opportunities for Drew students and area residents.
“An orchard is innovative,” Glass says. “I’ve been astounded by the support I’ve gotten from people for this. We’ve got lots of people ready to volunteer.”
All around us, trees are disappearing. But more are being planted, too. In the City of Falls Church, chief arborist Charles Prince and his team recently planted 800 native seedlings in forested areas. They intend to plant 500 more in the months ahead.
Back at Four Mile Run, Verweij says Arlington County has laid plans to expand the newly forested area near Bluemont Park all the way to the stream bank. As we survey the scene, he directs my attention to a bird box the county installed near the tree restoration site to provide a safe nesting habitat for native bluebirds. It would have been pointless had the trees not been planted first to draw birds to the location.
“It’s hard to be a tree in an urban area,” Verweij says. “You’ve got construction, air pollution, wind, heat, cold, dogs and human activity, and that makes it really challenging. But there are some really great trees around our urban corridors too, and we’re trying to improve that.”
Get Involved
Want to donate your time and sweat equity to growing and protecting the local tree canopy? Consider volunteering with one of these Northern Virginia groups:
Arlington Tree Connection
Earth Sangha
EcoAction Arlington Tree Program
Falls Church Village Preservation and Improvement Society Neighborhood Tree Program
McLean Trees Foundation
Plant NOVA Trees
Tree Stewards of Arlington and Alexandria
Proper Tree Care
As with humans, good health care is essential to maintaining trees’ vitality and longevity. Improper pruning, mulching and watering practices can inadvertently harm trees, as can invasive vines such as English ivy. For helpful guidelines on tree care and maintenance, click here.
Writer Kim O’Connell’s favorite tree is the river birch in her Aurora Highlands backyard.