Harsh fall weather hurt Treasure Valley trees

Homeowners across the Treasure Valley are saying goodbye to their trees after sudden harsh weather conditions last November killed members of several varieties.

Dale Dammarell, of Meridian, called a tree care company to inspect his lone flowering cherry tree. He removed another cherry tree from his backyard in March, leaving a stump behind. The remaining tree has since clung to life with numerous orange cankers riddling its branches, emptied of their usual leaves.

After an evaluation Wednesday with Idaho Tree Preservation, Dammarell decided to remove the 17-year-old tree from his property.

“I’m definitely disappointed,” Dammarell said. “These trees were great additions to our yard. They would make great, beautiful blooms every year.”

Weather conditions fluctuated between warm temperatures with highs in the upper 50s and 60s for the first two weeks of November before suddenly dropping to lows in the 10s and 20s across the Valley Nov. 12 to 19, according to the National Weather Service.

The types of trees that were most affected by that polar vortex include stone fruit trees — cherry, apricot, plum and peach — English walnut, willow, eastern white pine, maple and hibiscus.

Terri Ham, director of field operations and certified arborist for Idaho Tree Preservation, visits homes across the Valley and provides tree evaluations. Many trees she examined this spring are dead or show little signs of growth.

“A majority of the canopy is dead or attempted to leaf out, then wilted or just appeared and never really grew properly. The tissue was actually damaged from exposure or temperature or something to do with the environmental factors of what we believe to have been around that Nov. 13 snowstorm,” Ham said.

The frost damage may have varied by location, Ham said, as different areas of the Valley have warmer or colder temperature pockets.

Matt Pruitt, arborist at Terry’s Tree Service, has received an increased number of calls from homeowners this season regarding their trees. Many said that the trees, which were healthy last fall, are now dead or show only small signs of budding and growth.

“There are some customers where we work on their trees every year, and then they call us back this year and say, ‘My cherry tree died. My English walnut died.’ Trees that were perfectly healthy last year were dead this year,” Pruitt said.

Many of the trees Pruitt examined were damaged beyond the point of recovery. He has removed more than 100 trees so far this season, a number much higher than previous years.

“As far as frost damage goes, this is the first I’ve seen happen to trees around here,” said Pruitt, who has worked for Terry’s Tree Service for seven years. “A lot of our customers are clinging on to every last bit of growth they can trying to keep their trees alive.”

Ham said she hopes that homeowners who have to remove trees replace them with more hearty varieties.

Pruitt doesn’t believe the Valley will lose enough trees to have a significant environmental impact. Though trees have an effect on air quality, in summer, nearby wildfires have a stronger influence on the Valley, he said.

November’s problems were exacerbated by a drier trend in the local climate that makes it hard for plants and trees to adjust to weather conditions, Ham said.

“We’ve been seeing more trees damaged from winter exposure than we used to in the last three years,” she said. “A lot of evergreens have a lot of winter desiccation, and mostly it’s because of the cold, dry factor. ... We haven’t been getting the supplemental snow, winter moisture and the soil is extremely dry all winter long.”

Ham suggests that homeowners looking to increase their trees’ nutrients use humic acid, which encourages plant growth and cultivation.

Other advice from Idaho Tree Preservation: After irrigation is shut off in late summer, homeowners should continue saturating the soil around their trees to keep it moist through the fall and winter months. Water at the edge of the tree’s canopy once a week, alternating sides each week, and only when the air and soil temperatures are above 40 degrees and there is no snow cover. A rule of thumb: Provide 10 gallons per inch of the trunk’s diameter.

Pruitt recommends homeowners mix Zamzows Thrive fertilizer with soil at the base of the tree to provide nutrients throughout winter.

Recommended treatments are not guaranteed to cure or protect trees from future harsh winter conditions, Ham cautioned. Rather, they serve as preventive measures for homeowners to prepare their greenery for the fall and winter seasons.

Grace Gibney can be reached at 377-6444.

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