How will this weekend ‘s weather affect my peach blossoms? Should I cover them?
Multnomah County Oregon
Thank you for your question. The following MSU Extension article has a table (https://www.canr.msu.edu/uploads/files/PictureTableofFruitFreezeDamageThresholds.pdf) of thresholds that buds and blossoms can have before damage occurs. https://www.canr.msu.edu/news/freeze_damage_depends_on_tree_fruit_stage_of_development
In a related article, MSU recommends this for freezing temperatures: Air moving fans for improved air drainage - Using ground-based fans to increase the movement of cold air past obstructions and constrictions in natural drainage paths can decrease the likelihood of freeze injury during spring freezes.
I doubt that you have one available, but many fruit growing farmers use smudge (smoke) pots to create heat that helps protect the buds. I've attached a photo of one in a California orange grove. You might have a gas grill or some other heating mechanism that you can safely place near the plant. Hope these ideas are helpful. Good luck!
Would it help to cover the tree with a row cover, or would that knock blossoms off?
You can certainly do that but you need to be careful that the material is not so heavy that, when covered with snow, it breaks off the branches. You can also wrap Christmas tree lights around the tree, being certain it does not cover the fabric. And, as this article recommends, water the plant(s) well, since it holds warmth for the roots better than dry soil: http://marinmg.ucanr.edu/Our_Projects/Leaflet/How_to_protect_plants_from_frost/