Spring frost and blackberry blossoms

My prime ark freedoms start producing their first blossoms in February. I lost those early blooms to a frost. My kiowas and the freedoms are waking up pretty good now and I’m afraid I may lose what I have now to a late spring frost. Weather.com has been showing a couple days in the low 30’s next week here. I’ve seen references to 27 degrees F being that magic number. The blossoms I lost in February were to temps that I do not believe were that low. Any of you guys have first hand knowledge of how low of temps can the blossoms handle?

Ponca is just now waking up, Rosborough has a few buds breaking, sweetie pie the buds are just starting to swell.

These recordings revealed that inside buds that were still unopened the temperature dropped much slower than in opened flowers. However, unopened flowers froze at slightly higher temperatures than opened flowers. Above 28 F, no injury was visible, but when the internal temperature dropped below 27 to 27.5 F, all buds and flowers were killed. Frosts in which temperatures drop to about 27 F for a short time may not injure buds that are still tight because temperature inside them remain above the lethal range.

Found that online…


They did that testing with Tripple Crown variety.

I have seen several frosts take out my peaches and apples and even grapes… but never my illini blackberries or wild blackberries. Some of those have always made it thru.

Good grief, out here near the West Coast the early-bloom varieties of blackberry do not get started until the end of April. TC variety does not begin until late May. I don’t think I have ever read in a NWREC (our regional research station) publication about blackberry blossoms and frost.

My illini blackberries bloom and fruit over a pretty long period…

Ripe berries 6/15 to 8/5 or so depending on rain.

Blooming 4/15 to 6/15 … something like that.

A few years back we had 26-27 degrees on 4-15 after a early warm up. Took all my peaches apples grapes… but did not bother the blackberries or blueberries.