You can spread it all around the yard, assuming it's a typical potting soil, it's mostly organic material which will quickly degrade away. Most people just rotate their tomatoes in beds that are close to each other on a 3-4 year cycle and do just fine. I don't believe it's that mobile.

I'd stick it in a flower bed. It's not THAT contageous.....

Linda

You can use the pots for other crops.

Thank you everyone! I find it easier to empty the containers at the end of the season and store them in a shed for the winter. This is my third year and all my flowerbeds and pots are already full of "used" soil from previous years.

I buy the composted manure/soil from a local stable; it only costs me $20 for whatever I can hand-shovel into my truck. So refilling the containers with fresh stuff every spring isn't a big deal for me.

The yard has not yet been on the receiving end of the "used but still fantastic" soil, so that's where it will go.

Thank you all for your help! And the grass thanks you too!