The first step to breeding a new variety is to create a cross, a hybrid of the plants that have the desired traits. If the traits show up in the first cross, that hybrid seed (F1) is what goes on sale. An F1 hybrid will tend to be pretty uniform, so the breeder only has to collect seeds from as few as one plant, or many with the same cross. Assuming that the F1 doesn't have a breeding incompatability, you should be able to collect seed from your hybrids, and plant them out and select from the wide variety of F2 plants (second year), F3 plants (third year), and so on until you have an open-pollinated variety that closely resembles the F1 that you found desireable in the first place. You may even create a variety you like better. By always selecting the best plants and rouging out (tossing or eating) the undesireables before they flower and pollinate your more desireable plants, you'll be close to a stable variety in 5 years. It may take longer before your seed never throws an off plant, but it can be a fun experiment. The nice thing about breeding your own vegetables is that you get to eat the failures as well as the successes. Carol Deppe's book, Breeding Your Own Vegetable Varieties, is a good primer on the subject. Borrow it from a library and see if you want to get hooked on a new hobby. ;-) Catherine

The seed pods at least need to start changing to yellow. Completely dry is the best way to insure seed viablity. But full grown seeds if dried properly should be ok. When the pods are green they have not not fully developed.

Baby bok choy are just the regular bok choy but harvested young. These seeds are readily available from chinese grocery stores. I know several in downtown chinatown has these so you should be able to find them in a local chinese grocery.

I realize it's a little late to answer but it depends on how far along developed the seeds themselves are. If they were starting to darken in the pod then they should continue to mature if you pull the plant. If they were still completely green then I'm not sure they'd be viable. Rodney P.S. Bok choy is best planted as a fall crop. Spring crops can be hit or miss.