Blackberry winter has nothing to do with outages in service for the product from Research in Motion. Instead it is an expression used by old timers here in the mountains of North Carolina (and elsewhere in the Southern Appalachians) to describe cold snaps during the Spring when the blackberry bushes are blooming.
It is April 23rd and we just had a dusting of snow early this morning in the upper elevations (above 2,500 feet). My car thermometer read in the mid-30s when I got in it to go to work around 8:30 this morning. I'd like to say this is the latest we've gotten snow but I can't. I still remember when Mount Pisgah got 57 inches of snow on May 7th back in 1992. I had just planted my tomato and pepper plants and just as quickly repotted them indoors.
Blackberry winter is different from dogwood winter as it is later in the season. Dogwood winter is the cold snap we often get when the dogwood trees are blooming. We had an early and mild Spring this year and I think this is Mother Gaia's revenge on us for getting complacent.