We just endured one of our rare extra cold snaps for here in central South Carolina. Lows went into the mid-teens, with brisk breezes of 20-25 mph. The next day high reached around 34 for a brief time before heading back to around 20 that night. The following few days have been sunny and reaching into the 40's, but several nights in a row have continued to fall to the low 20's. Using the 6X250 Ultimate Row Cover, we constructed tent style coverings for each double row by placing pvc sections that were somewhat taller than the plants on each end of the rows. We used somewhat shorter pieces spaced at 5 ft intervals along the sides, and used these to secure taught lines of twine across the top and along each side. The fabric was draped over this to form a tent shape, and fastened securely with clothes pins. Even with the claim of protecting up to 10 degrees, I didn't expect the plants fair well after so many hours in the teens followed by repeated drops to the low 20's. This afternoon I peered under the covers with trepidation, expecting to see withered blobs. Instead, I returned to the house beaming. The broccoli, collards, kale, onions, garlic - even the the chard, lettuces, carrots and beats were all in good shape. They were even still getting enough light through the cover to not keep from developing chlorosis. The pansies and snapdragons are blooming away, unharmed. I don't know how much these would help in places with longer very cold nights for weeks on end, but they did a fabulous job here during our 10 hour per day of January sunlight over this 5 day stretch of a local snap. I highly recommend this Ultimate Row Cover for its ease of use, storability performance in breezy conditions, and better than expected protection that it provided my plants.