Since the exterminator's last visit, I haven't heard any more noise in the ceiling. There are still some traps up in the dropped ceiling. Once they are checked, maybe we can tell whether it is safe to go out there without wary glances upward. I haven't seen any more squirrels outside lately.
Most of my plant crops survived the squirrel invasion but tonight it is only 30 degrees on the closed-off porch. I hope they make it. Last summer a friend (thanks, Deanna) gave me some "Purple Queen" Tradescantia, which I propagated and tried out as a ground cover. The big purple leaves and small pink flowers were very striking. I took cuttings and have several pots on the porch for spring and summer. I was surprised to see Purple Queen featured in the White Flower Farm Spring 2008 catalogue. It is a great addition to hanging baskets or planters.
Squirrels, snow squalls and windstorms notwithstanding, my window shelves hold a lot of promise for happy gardening ahead.