“Potting soil” in its various manifestations can certainly be reused, though mixing in fresh ingredients and fertilizer/compost is useful.
I tend to dump used potting medium/dead plants into a communal garbage bag and compost them, or take a bag containing used, straight potting soil and dump it into an outdoor garden bed.
After a few uses I usually dump old potting soil in the vegetable garden or one of the flower beds, so there’s no waste.
Some of my potting soil is 30 years old. Shake the dirt off the plant roots at the end of the season, or after some bad luck, the plant gets composted, the soil goes where it’s needed. I recently found a place that makes a great blended soil I use for everything, as mulch, potting soil, for vegetables and bedding plants, $50.00 a cubic yard. Life is so easy now…
I voted never buy potting soil. I dig it out of the ground in our wooded area and put it in holes I’ve dug in my yard, or in pots. Then I put the crap dirt from the yard in the wooded area in the hopes that eventually it’ll stop being crap dirt. So far it seems to be working pretty well.
It depends. I have a chronic mealy bug problem in my enclosed patio. So I’ll reuse soil from elsewhere in the house, but soil from patio plants just gets tossed outside. My back yard lawn is slightly concave and becomes a swamp after a heavy rain (or melted snow). So I scatter all discarded soil on the lawn. Eventually it’ll even out.
From what I understand, there is potting ‘mix’ and potting ‘soil’. The ‘soil’ has actual dirt in it and is meant to be used in outdoor settings. Potting ‘mix’ is mostly stuff like peat or sphagnum moss, perlite and/or vermiculite, and maybe some fertilizer pellets (as in Miracle Grow.)
I reuse potting mix sometimes. The problem is that it can get bugs or various chemicals from the fertilizer can build up over time. Usually I throw used potting mix into the composter to add some bulk.
No real system but I tend to recycle it into my dirt and compost mix. I haven’t found a potting soil I really like for my bonsais so I mix my own.
Regardless of any distinctions being made here (potting mix vs potting soil), I read this thread with a big wtf look on my face.
Replace potting soil? How does that even make sense?
Anyway, what I do is, whenever I’m about to put something new in a pot, I dump out the old soil (whatever’s in there) into the compost bin. Fresh & ready “cooked” compost gets dumped back into the pot. Rinse, repeat. Really, once I started using the compost bin, there was no need anymore to go buy potting soil, potting mix, garden soil, etc. You can get all the benefits and nutrients you need in soil from composting, so I see no need to give Miracle Gro my money.