I would normally plant more peas than that. The individual plants aren't
as big as bean plants, and you lose a lot by throwing way the pods

Something to try next year is 'sugar snap' peas - the pod is edible too,
and unlike mangetout which have to be picked young, you can pick it when
the peas inside have swollen. So you get a bigger crop from the same
space, and are saved the job of shelling.

Thanks for the advice. M plot is only small, so only space for a handful
of peas (so I can have other things too). Bought some netting, a couple
of metal poles and some pegs this morning... now just waiting for the
rain to stop !
Also think I will pull up a third of the smaller plants and replant some
more seeds to lengthen the crop.