Last spring someone told me that Water Hawthorn pots could be pulled out and let to dry during the summer. In the fall they would come back stronger. I was skeptical but gave it a try. I left the pot sitting in the shade all summer in the desert heat. Then, a couple weeks ago I dug the tuber out and dropped it into the water. Pretty soon it starts growing again! I guess that in their native climates they go dormant in this way when the rivers/lakes dry up in the summer. Anyway, I'm anxious to see if it grows stronger this winter.