Here are some pictures of my spearmint plant that I am really wanting to do well! I've never had one before. What could I be doing to cause this? The leaves are turned black. And they are becoming sad and droopy. I feel like I am watering the plant so much. Could I be over watering it? The plant is pretty large, but I have a large container for it. I tried to separate to roots but they were really tough. Any advice??