I took on a second (small) plot next to my original plot. It was overgrown and contaminating all the other plots with weed seeds .... so I covered it in November and last weekend started digging the first bed. It is covered in couch grass and fairly heavy soil. I bought lots (5x3kg bags) of potatoes to help clear the soil and the first bag of earlies will go in today..... In answer to your puzzle though, I plan to leave half of the second plot covered until my stomach and back muscles feel ready for a good work out in the summer 8) .... if you keep your third of the plot covered until you have the energy to tackle it you can't go wrong.
Jane