All legumes need plenty of soil moisture. The best way of achieving this is to dig a trench in autumn and fill it will moisture-holding material such as garden compost, but even shredded newspaper and un-rotted garden waste can be used. Top off the trench with soil a fortnight before sowing or planting out to give the contents time to settle. Water well during dry periods especially when the pods are developing.

Broad beans
French beans
Peas
Runner beans