I just add it to low spots in the ground gardens. Given that I am several yards of topsoil short in some areas I don't think I will need to find another use anytime soon ;-)

each year - I will empty about 1/3 of the potting soil and then put fresh in. What I take out goes into my compost piles and then gets reused in the garden beds as top dressing. If you don't have gardens to use it in - the soil can be raked in your yard. It will enrich your grass and the soil there. Use a leaf rake to spread it so as not to damage the grass too much and then water down or do it before a good soaking rain.

ammend it with fresh compost's,and reuse it?

Unless your containers have had some disease problems, there is no valid reason NOT to reuse potting soil. Most of my containers are permanent plantings so repotting is relatively infrequent, but the more seasonal containers have their soil reused year after year with the additions of some new potting soil, often additional perlite, plus screened compost and slow release fertilizer.

I would think that the breakdown of the organic components of the soil and the overall deterioration of the soil structure would be good reasons not to reuse old potting soil. Am I overthinking this?

Andy

I don't think one season of use of previously fresh potting mix would break down the soil that much. Like others, I reuse but will mix with fresh soil in about a 1/3rd old to 2/3rd new and that lets me actually recycle the soil for new plantings. Most of my stuff is pretty stable (shrubs & perennials) and so I'm not doing that much repotting anymore.

I compost it.

I use it to pot up my extra perennials for my yard sale.

I reuse it. I plant annuals in containers, such as tomatoes and basil. When they are dead in the fall, I empty all my pots into a large plastic bag. In the spring, I add some manure or worm castings, bone-meal and bloodmeal. Mix it all up and use it to start planting my starts or seedlings.
caveat- I don't reuse the soil if a plant had some sort of disease or infestation.

Start a compost pile ... if you do not want it seen plant some schrubs or flowers around it... Great for old potting soil,dead plants,cuttings,ETC. ETC.

For those of us with small yards or none at all it creates a bigger problem not knowing what to do. Plus not knowing if there might be contaminates in the soil. One reply I read sounds pretty good. They said to pour boiling water thru the container let it drain then repeat, then put it all in a wheelbarrow and add new . They didnt say but would be good to add about 1/4 of good composted manure.

I have always reused potting mix. I purchase large bags of perlite, bark chips and some additional new potting mix, usually with things like worm castings added and refresh the old.

Wow, here's a thread that's ten years old and folks responded like it's yesterday! Blame Houzz for suggesting these ancient threads as somehow being relevant.

Reuse of potting soil seems to be a topic on a lot of people's minds lately. The best way to recycle spent soil would be to add it to a compost pile or garden bed. If you use it in a container it should comprise no more than a small fraction of the new mix or it could result in poor properties for the mix as a whole. There are numerous recent threads in which Al has provided a detailed explanation for why this is so.

I think your key word is "spent". Certainly that kind of soil in a container is useless, but if some soil is not quite spent, maybe it's OK to use or mix in with some other content, such as compost.

I do a combination of things. Some soil I have used for small plants or cuttings just for bringing in for the winter. In the spring, they would go into a bigger container for the growing season, but I don't toss the soil contents right away. I might put it into a container and mix with other stuff. All of that then might get used for certain plants that I either know don't need as much care in soil, or that I don't care as much for how they will produce.

For example, this year, I decided to pot up some extra canna lily tubers that I dug from the yard. I haven't decided what to do with them, but I didn't want them expanding more in the garden, and I didn't want them to dry up being outside of dirt either. For now, they are growing in pots with this frankenstein soil mix.

Other times, when I deem certain potting soil to be far gone, then I do add it to the compost pile. And yes, I have even added this extraneous potting soil to certain low spots in the yard also.