I had one million goes at naturalising them, getting seed from friends, buying plants etc. I think if you have a lot of mulch they will not seed themselves. The year mine all went berserk was when the mulch had gone and the ground was bare. Hate to be a smart arse but seed will most likely not come true to colour of th eparent unless you are in isolation and there are no other colours around. Each year when mine come up I think gosh, I never bought that colour. Also each year changes... there will be lots of pinks oneyear, another lots of blues. You have to thank those busy little pollinators for that. All I can suggest is that every time you see someone with a plant going to seed collect some and throw it around. Buy packets from everywhere and you will get some mad colours, forms, sizes, etc. That is the beauty of sexual reproduction... variety!! Also buy pots from mail order catalogues like Diggers, New Gippsland etc. Have fun. Pam