I collected seed from Lamprocapnos spectabilis (formerly Dicentra spectabilis) last year. I waited until the pods began to look a bit beige coloured and then tied small plastic bags over then loosely. Paper or fabric would be better but paper wouldn't survive our weather and I didn't have fabric to hand. So I used plastic but made sure they were very loose. When the pods ripened the seed simply fell into the bags. I then sowed them immediately into a pot of seed compost and left them outside for the whole winter. I finally saw sprouts in late March this year. They have now been potted into small pots to grow on. I find that I don't get much ripe seed even though they flower well and from the 10 or so seeds I sowed I have only 4 baby Bleeding Hearts.

Thanks flora. I have some tulle bags - I think I can slide those right over the stems and tie them on to collect the seeds. Even with low germination rates, it will still be cheaper than buying new plants!

If you have any old nylons or knee-highs, you can use them to 'bag' the seed pods as they ripen.