Frigid overnight weather turns into budding problem for growers.

Byline: Scott Maben The Register-Guard

The lowest nighttime temperatures to hit the southern Willamette Valley since early November are making fruit growers fret and putting a nip in otherwise radiant winter weather.

The low before sunrise today was expected to be about 20 degrees at the Eugene Airport, the National Weather Service said. It hasn't been that cold since the nights following Halloween.

Annette Pershern of Pleasant Hill has been getting up in the middle of the night to turn on large sprinklers in her family's peach orchards.

Coating the limbs in an insulating layer of ice actually protects the buds from the worst of the overnight freeze, Pershern said.

"It really does work," she said Monday. "It was gorgeous this morning, with the sun sparkling off the ice."

The danger of frost damage, which could set back this year's peach yield, is high because unseasonably warm weather a few weeks ago drew the trees out of dormancy, Pershern said.

"The buds are swelling and starting to show pink," she said. "Within a few short weeks, we'll have the flowers opening up. That's when it's most critical to keep them safe from the frost."

Daytime highs are reaching the low 50s, but winds of 20 to 25 mph Monday kept it from feeling too much like spring.

At 4 p.m., the wind chill made it a 38-degree afternoon.

Tonight will be chilly again with the low expected to be about 25 in Eugene. After that, the overnight lows will rise above freezing as clouds and chances of showers return to the forecast.

In the absence of a sustained cold spell, gardeners needn't worry too much about their plants, said Pat Patterson, coordinator of the master gardener program for the Lane County Extension Service.

Temperatures in the teens, however, could damage strawberry and boysenberry buds as well as emerging broad-leaf evergreens, including rhododendrons, azaleas and camellias, Patterson said.

The buds already are fully formed and some have started to flower, she noted.

"We would start losing strawberry buds and rhododendron buds right away" if it gets well below 20, she said.

"Now they're very vulnerable, so we could see a lot of blasted blossoms."

Some gardeners toss a blanket over vulnerable plants at night to shield them from frost damage, Patterson said.

"We're kind of hoping we stay in the 20s," she said.

Unexpected weather poses a series of problems for Pershern's River Bend Farm, which also produces strawberries, raspberries, marionberries, cherries, European and Asian pears and hazelnuts at the base of Mount Pisgah on the coast fork of the Willamette River.

Beyond fear of frost damage, she also worries that the blooms will come on well before the bees emerge from their hives this spring.

Orchard managers also are scrambling to prune their peach trees, to open them up to sunlight and help control disease, before the buds open.

GARDEN ADVICE

Worried about cold nights and vulnerable plants? The Lane County Extension Service can answer your questions.

Master Gardener hot line: Call 682-4247 from 9 a.m. to noon and 1 p.m. to 4 p.m. Monday through Friday.

Commercial growers: Call 682-4243

On the Web: eesc.oregonstate.edu/