Saw a video with Jim Duffy. He was showed compost in a bucket that he was reusing. Not sure why, but I dump my containers into the garden after one season of use. Have never thought to use it for more than a year. My compost is usually wood, leaves, grass, and some duck poop. I imagine after a season it is low on nutrients, but I spike it with compost tea. So what do you think? Reuse your compost / potting soil or dump it each year?