Thankfully I brought most of my tomato and pepper seedlings indoors on Monday night. They are now safely ensconced on a kitchen windowsill. I was going to let them take their chance with the predicted cold snap but at the last minute I ventured out into the Stygian gloom and bundled them out of what was becoming a very cold greenhouse. The few tomato plants which I didn't bring in are badly burnt by the frost, particularly those closest to the glass. There is nothing for it but to commit their remains to the compost heap.
The early potatoes, (first cousins of the tomato), are also displaying frost damage. I am hoping that it is only the growth that was poking out of the soil that has been affected and that the clawing tendrils of the frost haven't passed down to the tubers and turned them into lifeless mush. Time will tell. Perhaps some judicious unearthing is called for.