OAKDALE – Hundreds of dogwood trees bloom in late April in what could be considered an environmental miracle just up a hill from what was once an oil waste and mine runoff pond.
No one knows how this meadow of 550 trees made its way to property in Allegheny County scarred by decades of energy extraction, which is now part of an ambitious project to create the sprawling Pittsburgh Botanic Garden in Oakdale, said Jerry Andres, a volunteer caring for the dogwoods. Not only have these trees survived coal mining and natural gas drilling, but they also warded off a fungus that has killed many of their like in Southwestern Pennsylvania, Andres said. Meanwhile, this site also was timbered twice before workers began converting it in 2010 into the 60-acre Woodland Garden.
“We have so many native dogwoods that have lasted through all that,” he said. It’s amazing.”
Pittsburgh Botanic Garden in 1998 signed a 99-year lease with Allegheny County for this property along Pinkerton Road near Settler’s Cabin Park to transform 460 acres into the nation’s first public garden on an abandoned mine site. A year later, the group invested $200,000 in the plan and would eventually earn a $5 million state grant to redevelop the site.
The woodland area is the first section to open to the public, while extensive work continues on extracting residue coal, collapsing abandoned mines and reclaiming two nearby ridges, where theme gardens will be created, including one that will be named the Mister Rogers’ Garden of Make-Believe. All of this is 25 years in the making, said Andres, adding the woodland project began three years ago.
“This land went through a lot,” he said.
These Cornus florida dogwoods are native to Pennsylvania and can grow to 33 feet in height. Many of them are juveniles, which do not yet bloom. When Andres began to count and tag them, many invasive plants needed to be removed, including oriental bittersweet vines that grow up trees and strangle them. The invasive plants, though, likely helped the trees survive being trampled and eaten by deer.
To deal with the nearby mine drainage, workers used 450 tons of limestone to create a well to treat the acidic water and direct it back to the pond, which will become the centerpiece of a Zen meditation garden, Andres said.
The most amazing thing about the dogwoods is they never contracted the disease known as dogwood anthracnose, which has devastated the species across Appalachia, beginning in the late 1970s.
The botanic garden believes the trees are still alive because they prefer the acidic soil left behind by the mine and stand high on a hill that attracts a lot of wind, preventing the fungus from lurking, said Kitty Vagley, director of development at the garden.
“Our dogwoods seem to be perfectly healthy,” Vagley said. “That is what Mother Nature did for us. What was not unusual 30, 40 years ago is very rare today.”
The garden is open at this time only for special events and periodic “peek and preview tours” led by guides along the Woodland Garden trails. For more information, call 412-444-4464.