About an hour outside the city, just south of where the Shenandoah River crosses into Virginia, a farm is growing the most natural of crops for its terroir: trees.

Only these trees aren’t planted to stretch their roots along the river’s shore. After a few years of growing, they’ll be uprooted and trucked to a more concrete-oriented home, where they’ll provide shade and dozens of other benefits to the people who live there.

Though their bucolic setting makes it hard to believe, these are city trees.

The farm run by Casey Trees — the nonprofit charged with restoring, enhancing and protecting the tree canopy of the nation’s capital — grows many of the trees that are later planted in D.C.’s neighborhoods, schoolyards and open spaces.

“The goal is to produce 80 percent of the trees we plant in D.C. at this nursery,” Brian Mayell, general manager of Casey Tree Farm near Berryville, Va., said during a tour of the nurseries that currently grow about half of the organization’s stock (the rest is purchased from other nurseries).

The Casey family purchased the 730-acre farm that hugs three miles of the Shenandoah shoreline, known locally as Springsbury Farm, in 1958 and, in 2008, gifted it to the tree-planting organization that bears their name.

Just 15 of those acres are currently in nursery production, separated from the rest by tall deer fences. Besides the nurseries, the farm is home to several historic outbuildings, unoccupied horse stables and a sprawling mansion built in the mid-1790s.

The rest of the land is forested or leased to farmers who grow crops or graze animals, as they have for years.

“I don’t raise cows or hay,” Mayell says of the continued relationships with those farmers. “I grow trees.”

Growing their own trees allows the organization to home in on best practices for every stage of the tree’s life. The farm also focuses on growing trees that are rarely found at commercial nurseries or are more cost-effective to grow in-house.

“I don’t raise cows or hay. I grow trees.”

In 2011, the farm’s crew planted the first round of nursery trees, which grow for two to five years, depending on the species, before being transported to the city. As they grow, Mayell and his small crew watch them closely, taking notes on the planting and growing methods that appear to work best.

When a tree dies in the city, Casey Trees’ crews send its root system back to the farm so Mayell can take a closer look. A lack of water is still a main cause of death for trees (though likely not this summer, which has seen record rainfall so far), but sometimes a knobby set of stunted roots from a restrictive burlap bag could be to blame.

“I want to make sure I send out a good root system, so the tree has a good chance of survival,” Mayell said while examining a batch of root balls that had been returned to the farm.

Also visiting that day was a gardener from the U.S. Botanical Gardens, Anna Mische John, who was interested in the farm’s work to grow trees for an urban setting. The two talked shop about best practices for tree planting — balled-and-burlapped or bare root?

“In the toughest urban environments, there are maybe 10 species that will work,” Mayell says, drawing a contrast with the fertile river-bottom soils in which these nursery trees take root. “Everything does great here.”

The rural farm gives these city trees a great start, but Mayell relies on the rest of the Casey Trees team, including hundreds of volunteers, to keep these trees alive once they’re planted.

Mark Buscaino, Casey Trees’ executive director says one of the central purposes of the farm, beyond growing trees for the city, is to test its practices “on a continual process-improvement journey.”

He also sees the farm as a place to train better tree stewards and to showcase urban trees; long-term plans for an urban-tree arboretum, likely in Berryville, are in the works.

The farm hosts tours open to the public a couple times a year as well as educational programs. Casey Trees already works with about 1,400 volunteers to plant 2,500 trees a year, “but the growing of a tree is something that not a lot of people understand,” says Buscaino.

Growing them under close supervision — and close to the city — should reduce the learning curve while growing the city’s canopy.