SOMETHING HAPPENED WITH MY COLLARD, MUSTARD, AND TURNIPS GREENS. THEY START DYING. ANY SUGGESTIONS?

Are there any holes in the leaves as a sign that insects or snails are eating them? If so, it might be best to toss them out and start over. White spots on the leaves can be a sign of a fungus. Causes of fungal issues can be mild spring temperatures or high humidity. Another possible cause is not enough moisture. Greens grow best in rich, moist soil.