If your potting soil is something found in the garden center, I would add it to my garden after one season in the pot. My potting soil I buy from a landscape supply and it does not contain peat, only fir bark, builders sand and volcanic rock. After using it in my pots the only thing having been consumed is the fir bark, which I replace and add dolomite lime(one tablespoon per gallon)and a teaspoon of 18-6-12 timed released fertilizer again per gallon. My used potting soil is now ready to use again in my pots gallon and larger size. Good potting soil is almost $50 per cubic yard and is worth saving and reusing. Al

I also recycle ( reuse) my potting soil. I freshen is with bark and a little crushed perlite, add some soil activator from Roger's Gardens and its good to go.

I toss it in the compost bin to be recycled with all the newly added nutrients from the compost.... potting soil with muscle.

I use the recycled potting soil to build a berm around my newly planted trees that are in the ground. I always find that I need more soil than what came out of the hole (I use native soil to backfill so there is not much left) to build a berm to retain water after my plantings.