MEDWAY, Mass. — Many who attend their children’s soccer games at Idylbrook Park don’t know its there, but just a short walk from the parking lot, tucked behind man-made wetlands and a buffer of trees, something unusual is growing — an orchard of the nearly extinct American chestnut tree.

“Occasionally people walk their dogs back here,” said Gary Jacob, the volunteer who planted the nearly 600 trees, “but I don’t know how many people know this is here.”

Jacob planted the orchard in 2004 in association with the local chapter of The American Chestnut Foundation (TACF). The foundation has worked at a national level since 1983 to develop an American chestnut resistant to chestnut blight, an Asian fungus introduced in the early 20th century that nearly eliminated the chestnut from American forests.

Before the blight, the American chestnut made up one out of every four trees within its range. Its plentiful nuts provided food for humans and animals alike, while its giant stature, fast growth, and strong, rot resistant wood made it ideal for building barns or holding telephone wires. According to Jacob, some poles from before the blight still exist today.

Despite being reduced from one of the most common trees in the Appalachians to one of the rarest, not all American chestnuts succumbed to the blight. New growth often shoots from the base of blighted trees, and, in ideal conditions, can grow mature enough to flower. It’s because of these few remaining specimens that TACF may eventually be able to reach its goal of restoring the American chestnut to the Eastern forest.

TACF’s strategy for saving the tree is complicated. It begins with hybridizing wild American chestnuts — often called mother trees — with blight-resistant Chinese chestnuts. The result is trees that are half American and half Chinese that have 50 percent of the genetic materials needed to resist the blight.

Then, a careful, multigenerational cross-fertilization and selection process between the American/Chinese hybrids and more wild American chestnuts dilutes Chinese characteristics while maintaining the half-resistance to the blight. Finally, the semi-blight-resistant, mostly-American chestnuts are cross-fertilized with each other. If the selection process throughout the progression is true, then the most resistant of the resulting trees will be almost entirely American chestnut and have full immunity from the blight.

Unfortunately, as Jacob admitted, it’s an imperfect science. One might imagine tissue samples from each tree being sent to laboratories to determine which have maximum resistance to the blight, but, in reality, the selection process is much-less precise. Selections are based on visual assessments made by volunteers and measurements of blight scars that develop after the trees are deliberately infected with different strains of the blight fungus, according to Jacob.

“There are a lot of variables to consider during the selection process too,” said Jacob, who has observed that trees planted in the lower, wetter part of the orchard don’t grow as well as trees planted on higher ground. “It’s possible that a highly resistant tree growing in poor conditions could struggle to fight off the blight, while a less-resistant tree growing in better conditions could appear healthy.”

To make matters worse, the American chestnut must also contend with an invasive, parasitic wasp, and, further south, ink disease, which kills trees by attacking the roots. Jacob predicts the disease will make its way northward as the climate warms.

Only two or three out of a hundred trees get selected to be parent trees for the next generation. If volunteers like Jacob choose correctly, the American chestnut stands a chance. If not, 10 years of growing and nurturing an orchard could be a wasted.

Local diversity
In South Kingstown, R.I., another American chestnut orchard is growing. Both this one and the Medway orchard are part of the Massachusetts/Rhode Island chapter of The American Chestnut Foundation, which oversees 30 orchards within the two states. According to Yvonne Federowicz, president of this branch of the TACF, local orchards are helping to incorporate local genes in the restoration process.

About 12 years ago, TACF, based nationally in Virginia, began reaching out in states within the historic range of the American chestnut to encourage people to plant local orchards where semi-resistant American/Chinese chestnut hybrids developed in Virginia could be cross-fertilized with local mother trees.

“You want as much genetic variety in your population as you can finagle,” Federowicz said. Over the course of evolutionary history, local trees have adapted to local conditions such as seasonal temperature and day length variations, explained Federowicz. “A tree from Virginia planted in Massachusetts or Rhode Island may not behave the same as a tree native to the area.”

Having genetic diversity in the American chestnut population is also a hedge against the outbreak of future disease. In order to incorporate local diversity, the Massachusetts/Rhode Island Chapter of the American Chestnut Foundation needs 20 local mother trees represented in its orchards, Federowicz said.

Volunteers needed
The orchards in Medway and South Kingstown, like all of the chapter’s orchards, are volunteer driven and have benefited from strong partnerships. In Medway, Jacob, a wildlife biology major with an interest in forestry, has been the driving force behind the effort. In 2004, Jacob and his wife, Lin, began planting what would amount to about 600 American chestnuts spread over two adjacent orchards.

The land is provided by the town of Medway with oversight from the Conservation Commission. “The town has been a great partner,” said Jacob, noting that town officials provided access to an underutilized well on the property. Jacob used this water supply to build a drip irrigation system that nurtured the young trees until they could survive on their own.

The town also cuts the grass between trees in the orchard a few times a year at no expense.

In addition to planting and watering the trees, Jacob weeds, built deer fencing, injected trees with the blight and measured the resulting scars as they wrapped around the chestnuts’ trunks, choking the trees of nutrients.

Many of Jacob’s trees are now 9 years old and measure 20 feet tall. They are nearing the day when they will either be selected to spawn the next generation of trees in TACF’s restoration process or be destroyed. His wife only recently learned that almost every chestnut she nurtured from seed to tree during the past decade will be cut down.

“She was really upset,” said Jacob, who claimed he never intended to keep her in the dark. “Sometimes you make assumptions about what people know,” he shrugged.

That same feeling of regret about the trees’ eventual fate lingered over the volunteers at the South Kingstown orchard during a recent visit. “We speak very kind words to each tree before we cut it down,” Federowicz said, only half-jokingly.

In reality, each of the volunteers understands that eliminating the trees that can’t survive in the wild is the whole point of the project.

Unlike the Medway orchard, however, the South Kingstown orchard is comparatively bursting with volunteers. Thanks to partnerships with the South Kingstown Land Trust, which offered its property as an orchard location, and the Master Gardeners Association, which has hundreds of members in Rhode Island all looking to fulfill required volunteer hours, the orchard gets a lot of attention.

The South Kingstown orchard was planted in 2009, and since then volunteers have helped plant seeds, water trees, weed and build fencing. Gordon Jones, an engineer, a URI master gardener and an original volunteer with the South Kingstown orchard, built a solar-powered irrigation system that pumps water to the young trees.

Long-term project
“When you’re talking about forestry, you have to be thinking long term,” said Jacob. Since orchards in the final stage of TACF’s restoration process are just being planted now, it will be at least years before blight-resistant seeds are being produced, and then it will be an uphill battle to disperse the seeds throughout the species’ historic range.

“Chestnuts are heavy, they’re not going to be carried by the wind from one patch of forest to another,” Jacob said. “Even roads are major obstacles to chestnut proliferation.”

Assuming the logistics can be figured out and blight-resistant seeds are planted throughout the Eastern forest, it will be another 30 to 40 years before the trees are fully mature.

This raises the question of whether TACF can maintain this massive volunteer-driven project long enough to reach its goal of reintroducing the American chestnut to U.S. forests.

An orchard like the one in South Kingstown seems stable. A core of between 10 and 20 volunteers are maintaining the site and showing up for workdays, and with the help from the master gardeners and South Kingstown Land Trust new volunteers generally replace those who leave.

The Medway orchard is another story. According to Jacob, without his volunteer hours there is a good chance that the orchard would become derelict.

“It’s a matter of not just having a lot of people, it’s about always bringing new people along,” one South Kingstown volunteer said. “And getting more young people involved is going to be key.”

Orchard locations can also be an obstacle. According to Jacob, the town of Medway could decide to put the orchard land to another use at any time, without warning. Federowicz said the chapter has lost orchards in the past when volunteers have started orchards on their own property, and then lost interest before the orchard yielded anything useful.

Jacob works full time and spends a lot of time out of state for his job, but he still finds time to tend the Medway orchard. When he retires, he thinks he will stay in Medway, but can’t make any guarantees.

“As long as I am healthy and in Medway, I will be volunteering at the orchard,” he said.