Whenever Frederick T. Craddock steps out of his Arlington townhouse, 39 Leyland cypress trees are there to greet him.

The trees aren’t ancient — they were planted around the time Craddock bought his new home in 1996. But at 40 feet tall, the cypresses provide aesthetic relief from dense development in the Shirlington area and Interstate 395’s tarmac river.

The trees might not be there much longer. After construction on a new community next door began last year, the cypresses have turned brown, and ­arborists said they will not survive. Now, Craddock is among a group of Northern Virginia residents asking whether greenery can be saved as development encroaches.

“The trees are in danger,” he said. “When I press the people at Arlington County, they say, ‘Well, we do protect trees on public land, but homeowners are left to their own devices.’ ”

Craddock is a member of a small group of Arlingtonians trying to preserve the tree canopy in a 26-square-mile county expected to grow to 300,000 people by 2045. They are seeking help from lawmakers with limited power and developers who often have little incentive to preserve an arboreal landscape threatened by advancing blacktop.

Arlington enjoys a reputation as a lush, sylvan suburb — annually noted for its parks in one prominent national survey while also the home of tree-lined landmarks and neighborhoods. The most recent canopy study from the urban suburb, released in 2017, showed the canopy “appears to be staying constant” at about 41 percent, excluding Reagan National Airport and Arlington National Cemetery.

That’s slightly higher than the District but lower than some other larger neighbors.

Recent surveys show D.C.’s canopy at 39 percent, while the city of Alexandria, Fairfax County, Montgomery County and Prince George’s County have canopy coverage of 35, 50, 50 and 52 percent, respectively.

Arlington has been a center of the McMansion boom — new homeowners tearing down small postwar structures to build bigger ones that approach their property lines. The county’s population has grown from 190,000 to an estimated 237,000 in the past 20 years, according to census data, with more dense housing along the Orange and Silver lines corridor and thousands of jobs planned as part of Amazon’s HQ2 project.

“I’ve been here all of my life — over 60 years,” Craddock said. “We’re finding communities are being literally changed almost overnight.”

Whatever the tree count, Arlington officials say it’s not within their purview to do much about it on private property. Arlington County Board member Christian Dorsey (D) said that “the extent of power is not there.”

“We’ll directly engage with builders to see if they are willing to preserve trees,” he said. “What we can’t do is say: ‘That tree is beloved — you can't take it down.’ ”

Nancy Davis, a master gardener, moved with her husband to Arlington’s Glencarlyn neighborhood in 1978. The neighborhood was lined with silver maples.

“Trees were the major thing that attracted us to this neighborhood,” she said.

A generation later, she says, the attraction is slipping away. Many of the silver maples, which have a short life span, have passed on and have not been replaced as large, newer homes dominate lots that once included more green space. Developers may plant saplings, she said, but saplings cannot replace mature trees with limited room to grow.

Davis said she decided to take action and formed a Glencarlyn neighborhood tree committee in 2019, arranging a “tree tour” of the area and educating homeowners about basic tree care, like cutting back ivy that can “choke” vulnerable trees. She recently wrote letters to developers, asking them to help protect the canopy.

“The deck is clearly stacked in your favor rather than benefiting the Glencarlyn community, and every community, when it comes to cutting down trees,” read one letter sent to a developer in October. “We want you and all other developers who buy into Glencarlyn to know . . . We do not want to live in a neighborhood without mature trees.”

No developers replied, Davis said. She isn’t sure of the group’s next move.

“Our tree climbing days are over,” she said. “We are not going to do an occupation. The minimum we can do is let the developers know of neighborhood opposition.”

Anne Bodine, a retired Foreign Service officer and volunteer with the Arlington Tree Action Group, said she felt like she had “landed on a different planet” when she returned to a hyper-developed Arlington in 2010 after three one-year deployments to Iraq. Bodine urged county leaders to use a Virginia law passed last year — one intended to preserve mature trees to help absorb runoff that ends up in the Chesapeake Bay — to bring tree lovers some relief.

“Arlington prides itself on being ahead of the curve on all things progressive,” Bodine said. “No one is doing anything to bring that law into fruition.”

Del. Patrick A. Hope (D-Arlington­), who sponsored the bill that became law, said it encourages counties to protect trees because they improve water quality in the Chesapeake Bay watershed. He said county leaders already are “doing the best they can with the authority they have.”

“Arlington is much more sensitive to this issue than a lot of jurisdictions,” he said. “They are not the only ones.”

David J. Nowak, a scientist with the National Forest Service, said urban areas that want to preserve their canopies decades into the future should act now, noting it takes years for trees to mature. A paper he co-wrote last year said global urban tree cover decreased on every continent, except Europe, between 2012 and 2017 to about 27 percent. Development is a major factor in the decline.

“People have to have places to live and have to move around, but we have to preserve as much canopy as we can while allowing cities to function,” he said. “You can’t just discard nature.”

Bodine said she fears for the future of the county. She said she understands the need for more housing and economic growth but worries new construction will be both unaffordable and bereft of green space.

She said Northern Virginia shouldn’t come to resemble another region known more for its concrete than its trees.

“Maybe we’re old geezers and were just Brooklynized out of existence,” she said.

Matt McClain contributed to this report.