I assume your talking field peas. Regardless peas are not heavey feeders but if giving lots of nutrients and well tilled soil and moisture they will cover an area in vines. I find peas very hard to train up a trellis or any thing verticle. The seem to prefer to sprawl over the ground and if by chance a vine may go up. There is exceptions, Diawa or Botswana black eye climbed very easily up fiberglass poles for me. I would leave them be and let them sprawl. No need to add any additional nutrients the inoculant will help the peas produce their own nitrogen. As far as mounding up the soil I think that is a good idea. I typically hoe the peas once to remove weeds and pull soil up around the base after that the peas can choke out any weeds that may sprout. Rodger