When harvesting Broad beans last year I saved a few well developed seeds from the largest pods and dried them for use this year. This week, I sowed these, together with some recently purchased, in three inch pots. I keep them in our unheated conseratory until the plants are big enough to plant out.
Growing the seedlings indoors prevents mice from stealing the seed and the young plants will be protected from other pests until they are well established. I have heard that Broad beans make a good green manure crop, is that true?