Lethbridge’s ‘weird weather’ can be tough on trees

By Al Beeber - Lethbridge Herald on November 23, 2022.

Herald photo by Al Beeber Leaves cling to branches of trees along a boulevard in Riverstone.

LETHBRIDGE HERALDabeeber@lethbridgeherald.com

The potential impact of a late fall and sudden freeze on trees here may not be known until next spring.

Lindsay Bell, an urban forestry technician with the City of Lethbridge, says with southern Alberta getting so many chinooks, it’s hard to tell if there will be a die-off of some species.

“Lethbridge gets weird weather every year,” said Bell.

“A couple of years ago it was green ash, last year we had the drought, of course, and a lot of spruce suffered. This spring, nobody had any fruit on their fruit trees,” he added.

“It was just the way the year goes. We try to follow patterns but we get so many chinooks and up and down weather, it’s really hard to judge.”

Bell said on one hand the long fall may have been good for trees so they could store more sugars through photosynthesis. But it’s possible a change in temperature could make a difference, he said referring to 2009 when about 275 ash trees were lost in Lethbridge after the temperature suddenly plummeted to -17 in November after a long autumn.

Bunches were lost in an older area of the westside and in Park Meadows, where trees in the 30-35 year-old age class were getting up to the height of light standards, Bell recalled.

“Spring came and there were just dead trees here, dead trees there.”

He said irrigation can play a part in the tree deaths with some people not watering enough while others are always watering.

“With some of the birch trees, that’s part of the problem. People keep watering their birch (when) it’s nice into the fall and the birch trees aren’t hardening off properly so we’re seeing a lot of that on Simon Fraser,” Bell said.

“There’s so many variables in southern Alberta we just wait to spring and see what happens.”

Bell had a number of calls from people about sick and dying trees in Heritage Heights on the westside last spring which has a lot of lindens along the boulevards.

Bell said he tells people to give trees the time to leaf out in spring before deciding to have them cut down.

“It’s kind of a wonky place to grow trees,” Bell said.

“We could get a winter where we get a couple of really good chinooks and there’s no snow and it drops to -30. Then all of a sudden you’ve got all your root systems and there’s no insulation from the snow layer, and other years you’ll get six feet of snow and no snow.”

Bell, who grew up here and has lived in Lethbridge most of his life, said springs seem to take longer to arrive now and autumns tend to last longer.

“We’ll see how the trees react. A lot of the trees I think they kind of get used to it” but the weather can affect certain ages, he said.

Some years after tree planting, a lot failed to take root with the City doing many replacements, he said.

Fall planting here is not a good practice, Bell suggested.

“You get a chinook in February and the tree’s going ‘oh, it’s time to wake up’ and it’s not.”

Bell said residents need to learn how to water properly.

“A lot of people don’t water well enough and a lot of people use a lot of de-icing salt and shovel it around their trees. You see a lot of that downtown,” said Bell.

“Trees need supplemental moisture in Lethbridge. You’ve got to keep them in a half decent shape.”

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