Ok, so I did it; I planted my early potatoes, 'Rocket', on the 17th March, a week earlier than ever before. A combination of a fortnight of warm weather and the need to get my earlies up by mid-June (so squash can go in) kind of forced my hand. Unfortunately, when the monthly forecast was updated the same day, I was informed that there is a cold spell coming next week with the possibility of a run of freezing temperatures at night. Oops.
I did take some precautions when planting however. For the first time I actually checked the temperature of the soil six inches below the surface with a thermometer which was reading 48F (approx 9C). The reason is that potatoes won't grow in soil below 45F (approx 7C) so it was warm enough to plant. I didn't earth up immediately either; I usually plant in trenches then create a mound over the top but this time I just back-filled flat and covered the whole patch with black plastic. The plastic should soak up any available heat during the day and will stop the soil freezing at night. Obviously, I have to keep an eye on the bed as the potatoes will soon break the surface and I will have to start earthing them up, but hopefully this won't be for a fortnight or so yet. (I've done this in the past and missed the potatoes sprouting; when I peeked under the cover all the haulms were white and yellow. I thought I had ruined the whole crop but with a bit of sunlight on them they soon became green and grew on well).
In my 6 foot wide by 32 foot long beds I can get in 3 x 16 foot rows of each early and main crop. As the earlies are planted closer together I set out 15 in a row, a foot apart (this will be reduced to 10 per row for main crop which will be planted in April). I trench down to about 5-6 inches, lay the spuds out and add a general fertilizer. When I earth up I'll add some more fertilizer to the mound soil. Now it's a waiting game; if only I can outwit the weather this season ...
Just a quick update on some brassicas which were sown on the 9th March. There are 9 modules of Primo II cabbage; 9 modules of Trafalgar F1 Brussels Sprouts (above); 3 modules of Ruby Ball F1 red cabbage and 6 modules of Korfu F1 Kohl Rabi (below) (I'll start some more Kohl Rabi in a few weeks for successional cropping). In a week they have germinated in the heated propagator and have been transferred to an unheated greenhouse. I'll be thinning to one plant per station. That's it for this update, until next time ...