Cold Hardiness Warning

Cold hardiness tests performed this week on apple and cherry samples in Benton County suggest a risk of damage to cherry buds due to pending cold temperatures. While orchard management practices affect cold hardiness, there is currently a risk that temperatures will pass the threshold where damage to buds is likely to occur.

The following tables show critical injury temperatures for apple and cherry buds. LT 10 is the temperature at which 10% of the primary buds will be killed; LT 50 and LT 90 refer to 50% and 90% bud damage, respectively.

Apple Samples
LocationDate SampledCultivarLT 10LT 50LT 90
Prosser (Roza)March 18, 2013Fuji
20.4 °F
15.5 °F
10.3 °F
Gala
19.2 °F
15.0 °F
10.6 °F
Red
18.3 °F
14.5 °F
10.3 °F
Cherry Samples
LocationDate SampledCultivarLT 10LT 50LT 90
Prosser (Roza)March 18, 2013Bing
23.8 °F
16.7 °F
8.7 °F
Chelan
27.0 °F
19.1 °F
10.9 °F
Sweetheart
26.6 °F
18.8 °F
10.2 °F
  • From dormancy to fruit set, the flower bud undergoes a number of developmental stages that are associated with a progressive increasing vulnerability to low temperatures.
  • Freeze tolerance was analyzed using differential thermal analysis, this technique is only effective for cherries at early stages of bud development.

Washington State University