Start using heaters
Now that the days are cooler, heaters are a good way of protecting tender plants. Use a max-min thermometer to monitor temperatures so you know when to turn on the heaters. You’ll just need heat at night to begin with. Electric fan or tubular bar heaters are the easiest if you have power. If not, the options are paraffin or gas. Paraffin heaters are cheap to run but need regular filling and maintenance, while propane gas heaters are expensive but efficient. Insulate the greenhouse with bubble polythene or plastic sheeting to help reduce heat loss.
VISIT gardenersworld.com/ how-to for advice on winter salad crops
Position electric heaters in an open area, away from water sources