The Horrid F Word: Frost

The Horrid F Word: Frost

Erika DeBrouwer, Tree Fruit Specialist, OMAFRA

Some recent concerns about temperature drops have popped up in conversation with growers across the province. This “hot” topic is an opportunity to review critical temperatures, frost mitigation strategies and frost damage assessments.

Critical Temperatures

Apples	Silver Tip	Green Tip	½ inch Green	Tight Cluster	First Pink	Full Pink	First Bloom	Full Bloom	Post Bloom
Old temp	-8.9	-8.9	-5.6	-2.8	-2.8	-2.2	-2.2	-1.7	-1.7
10% kill	-9.4	-7.8	-5.0	-2.8	-2.2	-2.2	-2.2	-2.2	-2.2
90% kill	-16.7	-12.2	-9.4	-6.1	-4.4	-3.9	-3.9	-3.9	-3.9

Frost Mitigation and Assessment Resources

• Frost mitigation factsheet
• Frost mitigation strategies article
• Frost bud assessments