Wasatch Back Trees Under Stress Even With Abundant Blooms

Aug 9, 2018

A prolific Mountain Mahogany bloom is underway along the hillsides in the Snyderville Basin.  The Japanese Lilacs produced an abundance of flowers this spring throughout Summit and Wasatch Counties and fruit trees are producing bumper crops. Some experts say despite the fruit and flower displays, trees are under stress in the Wasatch Back.  Carolyn Murray has this:

Jason Barto is certified with the International Society of Arboraculture and is the Executive Visionary Officer of Releaf Utah. Releaf is a non-profit dedicated to getting more trees in Utah. They started with a focus on the Wasatch Back but now it extends throughout the state.

He says they don’t have conclusive evidence or explanations for the variety and volume of the tree blooms this year.

“Last year we had two apples out of 30 trees and this year it looks like we’re going to have a bumper crop. I’m seeing the same thing on my choke cherries, both my Canada Reds and on the native Choke Cherry are having lots of berries. For us, up here, it’s probably the fact that we didn’t have a June or July snowstorm. At the same time, we are seeing a lot of stress, because of the lack of water, on the trees. They’re putting out our flowers and they’re looking great but we have a lot of trees that are under stress because of the lack of water.  It’s a long-term issue that doesn’t get resolved in one rainstorm or one precipitation event.”

He says the long drought has put a lot of stress on trees in the area. He says the roots go down two to three feet and slow, deep watering is one way to keep them healthy. When trees are stressed, they are more susceptible to pests and fungus.

There’s visible browning on many stands of fir trees in the area.  He says he doesn’t think it is the bark beetle which is a common pest on coniferous trees throughout the western US.

“That is likely the Balsam wooley adelgid or as the cool kids are calling it, the BWA. It’s a pest. It’s hard to describe and I’m not an entomologist. It’s described as a tiny sucking insect that came from Europe. It’s an invasive and it’s taking advantage of the trees that we thought were going to be relatively attack free. You know we’re worried about our Spruce with the Spruce Beetle and worried about our Pines with the Pine Beetle coming through.  We thought those critters had eaten themselves out of an hospitable area and that we may be able to take a breath and nope…here comes the BWA."

Barto says the Aspens in this area have a fungus that appears on the leaves as brown pigment. He suggests removing the leaves and twigs that have fallen to prevent the spores from spreading. Disinfecting clippers and chainsaws after contact with the tree is also recommended.

“It’s likely Marsennina. That’s the most common one that we do see but we see two others out there. There is a chemical treatment.  It takes several applications of the anti-fungal to really stop it."

He says a lot of local aspens have a blight called Cytospora Canker.  Bartow says a healthy tree has natural defenses to fight off disease and pests. 

“It gets back to the simple…take care of your tree.  Plant it right and take care of it. Make it a strong tree and it has natural defenses to fight off a lot of these pests. An attack isn’t going to be that damaging to the overall health of the tree.  Eighty to 95 percent of the aspens in this area have it and it just expresses itself more aggressively on stressed trees.” 

Barto says there are qualified, talented tree specialists available in the Wasatch Back region.  He recommends using an ISA certified arborists to evaluate and treat trees suspected with disease.