They are calling for near freezing temps tonight and tomorrow night. I'm so sad, I had little sprouts already. O well, I guess I will be re-seeding in a couple of weeks. I was just too impatient to wait any longer.
Can you cover the plants? Your soil may be 20 above freezing. For single plants, I've driven stakes beside the plant and wrapped plant & stake with newspaper, held down by pebbles - little teepees. Cutting the bottom off a plastic milk jug makes a good cloche. The lid should be taken off during the daytime.
Cold weather can really delay growth but near freezing isn't the same as freezing. A few things can take a light frost without harm. I'm sorry your weather has taken a turn to the cold.
I do have a bunch of empty milk jugs. I'll try to protect them with those. I'm hoping that since it will only be NEAR freezing that everything will be ok...
Another way of protecting direct-seeded things, if they are in rows or blocks and thus not easy to put boxes or milkjugs over, is to toss down something twiggy on top of the emerging seedlings (evergreen boughs are ideal, but twiggy dead branches work ok too -- you want 'em pretty flat to the ground, not sticking way up) and throw an old sheet over top.
I have been using cut milk jugs and 2 liter bottle to cover my plants when they call for near freezing nights. I also had been covering my earlier plants in plastic. To keep the plastic off the plant, my husband built me wooden skeletons to sink into the raised beds to lay the plastic over.
Come next winter, I'm using the wood skeletons and plastic to create mini greenhouses out there so I can continue growing fresh lettuce and spinach all winter.
I think they will be ok.... I've been doing this with my plants since Feb and we're in the same zone. So far everyone has survived. Some are just growing slower then others.
I had a few sprouts too...then the blizzard hit. I am not giving up hope though. The snow covered everything very quickly. Many times plants are nice and snug under the snow and do fine once it melts.