growing peas

 this year's pea crops have been very good for us and i have to say my wife made a good job of planted the seeds in pots then we  transplanted them  on the allotment we grew them up rabbit wire and they turned out well good picking

but what i can't get my head round is field grown peas not just a row or two but many acres on the ground no nets no wire then harvested by a large machine no hand picking in sight then of to the factory so how do they do it?

here we are  putting  bird netting round our pea crops to stop those darn pigeons  so do you need to sow peas up sticks or netting hedge cuttings where used after the hedge was laid in the winter months by many an old gardener so is it still the best way for us gardeners to grow our peas up sticks or netting or just grow them on the ground ?