I dump used potting soil out into the garden. However, I will continue to use it - especially the very barky stuff I use for my JM's and conifers - until I think it has broken down too much. So it may go through a couple of repottings with just some refreshing with new potting mix.

Thanks for that Gardengal

Stephen UK

I throw mine into either a compost pile or another garden. After all, earth is nothing but a lot of decomposing matter! :)