Weeping willows

CHARLO - Charlo's Palmer Park has long been a place of serenity, an oasis of shade and sparkling water amidst a sea of dry, hot grass.

Its staple, weeping willow trees, most of which have been around for more than 70 years, provide shelter from the hot sun for all kinds of community events. Now, thanks to a series of single-digit temperatures last October and the emergence of an infectious canker, many of those trees are suffering, or completely dead.

Sue Palmer, who owns Palmer Park with her husband, Skip, said this has never happened before, and it's been devastating.

"It's not as picturesque," she said of the park, which is home to many weeping willow trees that used to serve as a lush green vale, reaching all the way to the ground.

Now, the trees are a mix of fresh green and crusty brown tendrils, with most of the life wrapping itself around the trunk and barely extending toward the ground.

"A few of them aren't going to make it," said Palmer. "We're going to have to take them down because as large as they are, they would just never look right as a weeping willow. Those that we do decide to keep are going to have to be radically trimmed."

The October freeze, which took place before the trees were in dormancy, literally froze the trees' leaves in place, Justin Jennison, with Jennison Tree Experts in Polson, said. Many trees didn't lose their leaves this year and still have dead leaves on the trees.

"The sudden freeze last year hit so soon that it froze the cells and water didn't have time to migrate down the tree to the root system," Jennison said. "It caused internal rupture and ice that leads to the tree dying. Smaller diameter limbs died because they didn't have the insulation."

Skip Palmer said he plans to put hard woods in place of the dead willow trees that must be removed. Based on a recently released article from the Montana State University Shutter Diagnostic Lab, Palmer believes that while the weather did stress the trees, it is not entirely to blame. He thinks a disease, called the Cytospora canker, which infects trees through the bark moved in due to the trees' weakened state.

"That early frost caught the willows and ornamentals with their leaves on and started the whole thing," he said. "The trees got stressed because of the weather, but now the canker is picking up on it."

All prime symptoms of the canker, Palmer cites the characteristic discolored blotches, the trees' failure to leaf out, and the gooey substance oozing under the bark.

"If you peel it off, it's just slimy," he said. "If it was just a weather situation, I think it'd be spotty, but it's on every tree, all the tops and especially the north-facing sides, which get hit with the north wind."

According to Jack Stivers, of the Montana State Extension office, it's not just the willows that suffered, but also rose bushes and the hybrid poplars: shade trees, which are fast growing, have a nice spread and big leaves.

"A lot of introduced trees have had exposure to not-normal temperatures," Stivers said. "They're just not able to handle the extreme long-term conditions here."

While the native willows are doing fine, almost all of the ornamental and introduced species show some degree of damage. Now, it is rare, Stivers said, to see a weeping willow that hasn't been severely damaged.

"We see a little bit of damage every year with either spring frost or fall cold. There's some die-back," he said. "The severity of October, 2009 just really took out the ornamental trees."

Cosmetically, structurally and developmentally, Stivers said it will be years before the damaged trees recover. Property owners must determine their tree's degree of damage and what is the best way to deal with it. Leaving a dead tree in close proximity to a home or livestock is of course a risk that must be factored in.

"My suggestion is to make a decision on what they want that tree to be in five years," Stivers said. "Can they revive it with pruning, taking out the dead and dying branches? Is there an opportunity to replace it with another species, or is it better not to have a tree there at all?"

Palmer said his plan is going to be aggressive pruning, using a saw dipped in 70 percent alcohol between cuts to prevent the spore from spreading.

"I'm not going to give up," he said. "I'm going to continue to trim like I always do. I'm going to replace them with another tree and hope it doesn't get it again. I wish it was an easy answer, but it's just not."