Same thing happens every year, at least since we routed the kitchen/laundry drains to the back yard: tomato seeds get washed down the drain, they find their way into the yard, they sprout. This year’s a little different: they got started early enough that we might actually get some tomatoes off them this year. I don’t see any frost in the extended forecast — these days, first frost ends up being in November often as not — so that helps too.
As you can see, I’ve put some cages up for support. What you don’t see is the few shovels of compost I’ve thrown around the roots. Funny how the directions with potted tomatoes say “bury ’em deep!” when they have no trouble at all putting down roots from the surface.
I guess I really need to put a bed out here for next year, and see what happens when drain water gets to work with a planned garden bed for a change.