If they're going out into the garden later then give them 4" apart? & 7 per pot, 6 round the outer and 1 in the middle, beans & peas?
We grew some adante dwarf french beans in a black recycling box last year, they gave a reasonable crop. I think we put about 12 plants in, this year we've put 9 (3x3), but they're not the biggest dwarfs!
