Here I go with that old adage...The coldest winter I ever spent was a summer in San Francisco. At least the western half of SF that gets the marine layer, aka FOG. I put the heat on briefly for many mornings throughout the summer because it gets so chilly here. Doesn't bother the roses however so I can't imagine what you folks in the real freeze must go through to protect your precious plants. When I lived in NJ I wasn't gardening so paid no attention to the frost. Diane

Plants are very ineffective at taking up water when it's very cold. Watering before a freeze period is important and sometimes essential for some container plants depending on how long the freeze may be. It also helps create a moist/humid environment (especially under covers) which is better for most plants than the dry air that tends to come with a cold snap. The two combine to create a turgid plant that can better survive the cold snap and provide a less extreme environment to do it in. It's all about keeping the plant on a slow/steady path to warm-cold-warm-etc. more than it is about making sure the plant isn't cold. During this time if high winds are a concern you really need to keep an eye on anything tender or in containers. The uptake of water is slowed during the cold period to the point where some plants can dry out pretty quickly. BTW, if you see frost on your plants...leave it alone. It may damage your plant, but removing it (especially with water) will do more damage to most plants because of the sudden temperature change. That one is just a general guideline, though.

My sympathies. I would do a sheet drape though I think they may be OK since I am fairly sure that my newly sprouted plants have survived below freezing temps as long as it isn't really low. If you will have wind, clothes pins may help hold the sheet in place.

I'm in SW OH and had the same problem. I lost nearly all my grape blooms, so there'll be no fruit on them this fall. That was even after I tried to cover some of them. I've held off planting tomatoes, peppers, and squash because its been too cold. They're all in the garage overnight, but show signs of having outgrown their containers and need to be in the ground. I'm hoping this weekend is the ticket. Hope it works out for you.