Hello,

I am new to seed saving and need advice. I have read that members of the Brassica (cabbage family) easily cross pollenate, but not within a particular species. Therefore if I want to grow a brassica rapa (Chinese cabbage variety) and a brassica oleracea (kale/collards etc) together that this is okay; is this true? I have also read that these plants are self-infertile meaning that they typically cannot self-pollenate and produce fertile seed. So, if I want to grow a true growing purple pak choi but I don't want it to cross pollenate with another brassica do I simply need to exchange pollen from two flowers on the same plant OR to grow two pak choi plants and allow them to cross one another, even if their seeds originated from the same parent plant? Please advise. Thanks!