I have just taken over a new allotment and have started turning it
into beds 1.5M wide and 6.5M long. The soil is in good condition and
has been well manured. I want to get some maincrop potatoes started.
Deep beds will allow closer planting but this could give problems
earthing up. I would like to try planting under black plastic. Has
anyone done this? What problems are there?

fiffer