Kathleen : thanks, it would be great ! What do you mean by species ? Do you mean (i) different species of Cardamine or (ii) different generations ? If (i), it can't be the case because we only have C. hirsuta here. If (ii), I know :-( But we do not have much issues with controlling it before it recreates its seeds stock during summer. * Dr. Christian M. Lachaud, PhD* _________________ http://www.saffron-crocuses.com/