1). how big is the pot where the mini-rose bush is growing in, you may need to change pots, 2). is it warm where you have it? if its too cold for the plant or too hot the plant will begin to die, and 3). how much water are you giving the plant itself? Too much water will drown it and the leaves will yellow and fall off, too little water and the leaves will yellow, turn brown and then fall off.