personaly i think you treat them badly ie in the bin lol . on a more serious note bamboo or doctor bob will definatly know . take care bye for now .

Also, where in the world are you, Tank? We don't need to know your address, but we need to know something of the climate that you grow in. If you are growing them in a hot summer, mild winter climate, I might be able to help you. If in a mild summer, cold winter climate, Moon_grower's advice would be more helpful. Try clicking on your own icon, and editing your profile to show your general location.

It could be anything from over-watering, to not enough ventilation, ie planted too close together, to the numerous bugs all brassicas are susceptible to - white fly, black fly etc etc. Can you give us some more info?