I will be re-using it and, now that I have some compost bins going, I will be composting leaves and possibly even stems. If I have an Plant with bug issues, though, I’ll be burning them. I was listening to Jeff Lowenfels and he leaves all the roots in his pots and just pops another seed and goes right back to growing! Lol!
I’ll be leaving the roots in there but I’ll add a few amendments and compost the soil for a time before re-using. This winter all my used soil will be in a pile and planted with a cover crop of green manure, to get it ready for next spring’s containers.
Lots of people think that there’s plenty of remaining nutrients in the soil, if it was properly built in the first place and that the key, at that point, is the microbial life. If the soil has the right microbes it’ll allow the plant to pull out the nutes. That is to say, in an organic system. My ultimate goal is 100% organic and water-only soil + aerated teas. No bottled nutes. We all gotta have a dream, right?