Potassium is BAD for the kidneys when there in the end stage o kidney failure. Spinach, potato and tomatoes are bad for kidney patients, beetroot is good, parsley is good burdock is also good and carrots. Also since when is banana good for kidney? Will this Potassium Broth recipe bring the potassium up, if it does, then it's BAD for the kidneys. BTW - no burdock seeds cant be used to make the tea, burdock leaves must be used.