In the article Growing Sugar Snap Peas in a Container, I commented on the variety I selected being cold tolerant down to 28 degrees.  I inadvertently tested that claim.  I have the peas growing in 12" x 18" grow-boxes on the patio. I cover them with gardening fabric at night.  Well, I took off for the evening without covering the peas.  A fast moving snow storm rolled in and dumped three inches of snow on the ground - including my patio.  The peas sat in the dark under that cold blanket of snow for four hours before I got home.  I looked at the snow covered peas and was sure it was colder than 28 degrees and that I had killed them.  I quickly brushed the snow off the peas and covered them for the night - hoping for the best and fearing the worst.  Well, the new day dawned bright but cold.  After a few hours the patio had warmed up to 38 degrees.  So, I took the cover off the peas to find them tall, perky and no worse for having been smothered in snow.  It's wonderful to grow a vegetable plant tough enough to survive my neglect.