As a time for planting indicator I have always tried to plan to get most of the planting done between the last two weeks of March and the first two weeks of April.
The up side of this prolonged very cold spell is it has been dry and we have needed this as the land is in such a poor state: in a very compact condition with very little air spaces and will take much longer to dry out and will remain slower to warm up.
We are finding, whether freshly ploughed land or over wintered ploughing, the land must be moved to allow air in and drying to take place, which means we need long spells of dry weather and drying winds.
We started planting at the beginning of March in between the snow showers. All the crop is covered in fleece to protect and warm the soil up and for some varieties we put a layer of polythene on as well, with holes in because under a full plastic sheet the temperature can rise too much and damage the plants when the sun shines all day. The temperature lift achieved is 2 to 4 degrees which does not seem much but is vital in enabling us to start harvesting on time: ever the optimist.
I must say a big thank you to our planting teams for enduring such bitterly cold conditions during these last four weeks. They have not faltered at any time and, to try and help keep their spirits up and them warm, we have run a soup kitchen at lunch time: excellent team work.