Bitter temps in November hurt trees

WENATCHEE -- Possible single-digit temperatures this week probably won't affect local crops, at least no more than they already have been hurt by an earlier cold snap.

That's the assessment by Tim Smith, Washington State University extension agent for North Central Washington. Smith, who specializes in tree fruit crops, has been giving talks at several horticultural meetings this winter on the serious damage that may show up as a result of a devastating cold spike Nov. 23-24.

Fieldmen and orchardists have been reporting widespread damage to tree trunks and limbs, he said. Soft fruit trees in the Yakima Valley may have taken the hardest hit. He said vineyards may have been seriously damaged as well.

Temperatures dropped to 4 degrees below zero in many Wenatchee-area orchards Nov. 23 and early the next morning. Some low-lying orchards recorded temperatures of minus 8 and lower.

It was even colder farther south. Temperatures dropped to minus 20 in the Columbia Basin and minus 18 in the Yakima Valley, where the bulk of the state's apple and soft fruit crops grow, Smith said.

Temperatures this week aren't that cold in comparison. But the real difference is in the timing of the cold, Smith said. Fruit trees and other plants still are deep in their winter slumber at this time of year and tolerant to temperatures well below zero. Local temperatures were unusually mild the past couple of weeks, but it takes a lot of 40-degree-and-warmer days to make trees think it's spring and make them more susceptible to cold injury, he said.

The record low temperatures in November came before the plants had fully hardened for the winter, Smith said.

More winter injury will show up this spring, he predicted. But the damage has already been done.