YANKEE SPRINGS TOWNSHIP, Mich. (WOOD) — Bob Ross and his “happy little trees” are popping up in state parks across Michigan.

Signs bearing the face of the late public television painter and his catchphrase are part of a newly renamed replanting program that helps parks especially hit hard by invasive species.

At the Yankee Springs Recreation Area, entire groves of ash and oak trees have been wiped out by emerald ash borers and oak wilt. Statewide, millions of trees have been lost.

“It’s sad,” Yankee Springs Park Ranger Brad Bedford said. “I’m a nature lover, so I don’t cut down trees unless I absolutely have to, unless they are dangerous and a threat to our guests.”

Infected trees lose their leaves, become brittle and eventually topple over, infecting more trees in the process.

“Once a tree is infected, there’s not much we can do,” Bedford said. “We cut them down and try our best to replant the areas especially hit hard.”

The Michigan Department of Natural Resources has a replanting program. It used to be named the Department of Corrections Horticultural Planting Program but is now the Happy Little Trees program, the new title coming from a partnership with Bob Ross Inc.

The trees are grown by state prison inmates — prompting the nickname “prison grow” — and then taken to parks, where they’re planted by volunteers.

“With the name change, we’ve been able to recruit more volunteers,” DNR Natural Resources Steward Heidi Frei said. “As these trees are released from prison, they’re coming out and ready to go into the field throughout the state.

“We’ve seen people travel from across state lines just to get one of the Bob Ross T-shirts,” Frei continued. “People want to look toward something and someone who has a positive message and that really aligns with what we want to do within DNR Parks and Recreation Division.”

Since the program has been renamed, nearly 1,000 trees have been planted statewide, 65 of them at Yankee Springs.

“We had our entire ash population wiped out a few years back. Our oaks are suffering in certain areas of the park,” Bedford said. “But we’re planting red maples now: trees that would naturally be found here as well, but trees that are a bit tougher.”

Bedford and the department agree that the problem of invasive species stems from campers. 

“When people camp, they bring firewood with them,” Frei said. “Sometimes firewood can harbor pests, like we found with the emerald ash borer. That’s how emerald ash borer spread so quickly throughout the state was through the movement of firewood.”

Oak wilt is no different. 

“It’s a beetle,” Bedford said. “It infects the tree and then the tree gets sick, spreads out through the roots and through other oak trees that are in the proximity. It can be catastrophic.”

The DNR hopes Bob Ross’s positivity will extend through the volunteers into the trees and then the campsites.

“Look around,” Bedford said. “This is what we’re trying to protect. We encourage people to buy the wood locally or from the park. Don’t bring firewood in the park… That’s how most of these pests and invasive (species) happen and we could lose even more.”