Last year I grew lots of lupins for friends. As they developed I potted them on to larger pots and kept them on capillary matting but this year they were covered in white powdery mildew, I treated them with roseclear. My question is will they continue in the future to suffer from this mould , if that's the case it would be unfair to give them to anyone. Should I destroy them and start again . What can I use to sterilise the matting. All advice greatly appreciated.

Thank you Chris for replying. Yes earlier in the year, maybe April, they had completely dried out and it was after this that I noticed the mildew. I'm relieved that I don't have to dump them. Thanks for the link, it was very informative.