soil Re-using potting soil mix from last year?

Before I go ahead and (potentially) do something stupid, I'm wondering if anyone has any opinions on the re-use of soil used last year. Details that may influence your response:
 
  • Fox Farms Ocean Forrest mix - Used last season, outside
  • Sat outside throughout the winter, several weeks of below freezing temps
  • The containers used are about 15 gallon in size, fabric
  • Roots of the plants from last year didn't reach the bottom or sides of the containers
  • I have replacement nutrients to add to the soil for this year (a bat guano-based supplement)
  • I also plan to add more perlite to the existing mix
 
I spent a ton of cash on soil last year, and I would love to not do that again. :-)
 
Thanks for any advice you may have!
 
Yes, this is usually a great idea because a lot of the stuff in the soil has had the time to break down and is usually rich in nutrients. You can even leave the roots in if you break them up and mix it around. Just add whatever nutes and it will work fine. The only words of caution I have to extend to you are that occasionally, bugs and whatnot lay eggs in the soil and if you plan on using that soil indoors, you may have problems. Also, if any of your plants had any diseases, the soil isn't safe. 
 
Awesome. Thanks! Luckily no diseased plants last year, and I won't be bringing any of this stuff inside.
 
peppamang said:
Yes, this is usually a great idea because a lot of the stuff in the soil has had the time to break down and is usually rich in nutrients. You can even leave the roots in if you break them up and mix it around. Just add whatever nutes and it will work fine. The only words of caution I have to extend to you are that occasionally, bugs and whatnot lay eggs in the soil and if you plan on using that soil indoors, you may have problems. Also, if any of your plants had any diseases, the soil isn't safe. 
 
 
Sure!
So long as the soil isn't accumulating salt or an overabundance of calcium from hard water, you can re-use the stuff indefinitely.  Just plan on augmenting it with some good fertilizer of some sort.  Cow poo is cheap and easy to mix in.  Or water in some fish soup, bat or worm poop, or some other good organic fert.
I've had mixed results adding chemical ferts to old soil - likely a result of me doing something stupid.  I can't see any reason "chemical" ferts wouldn't work just fine.
 
Before proceeding, you might want to take a sample to the local nursery for a PH test.  Calcification tends to drive the PH to undesirable levels, potentially causing nutrient uptake issues.
 
As for salt, a good rinse is all that's required to reset the clock.
 
I'm not really offering advice either way, I'm NOT against recycling, but I used to recycle soil for my medical plants (I use medical plants as an example because they're even more sensitive, better than false positives). I also used almost the same original mix and also paid a pretty penny each time.
 
One thing that I noticed was that every time I recycled soil, the material itself became more and more compacted and heavy (as noted by Solid7 to watch for). I started to get hermies (again, I know they're not peppers, but this is a good indicator that something is wrong). The main problem is the roots weren't given the space they needed to spread and the soil held water too long.
 
Ever since, I have now resolved to buying new soil each time for my medical plants and will recycle lightly used soil from this (soil from culled males or problem plants that didn't see a full life cycle) for my pepper plants, but only once recylced and only lightly used at that. The rest gets dumped as top-soil all over my house and/lawn.
 
Also, to combat the price, I minimalized my soil to just (4-to-1 ratio - about 1 bag of each mixed together) Promix HP and fox farm ocean forest. just one bag of each will fill 5 full-sized storage totes just about to the brim. So for around 60 bux, I can pot up quite a lot of poly bags. I happen to have a large bag of azomite dust and humic acid, from which I toss a small handful of each into the mix with a small handful of epson salt. That's pretty much it. Yields a nutrient-light mixture which I still feed on a regular basis (as needed, of course). ***the azomite and humic acid were bought in bulk at a gardener's supply store (stuff gardener's and maintenance crews buy, it's diluted, but even one bag should last my whole lifetime).
 
All that being said and to reiterate, for outdoors, I won't hesitate to recycle that lightly used stuff once. After that, it goes to the general garden/lawn areas. In this way, I also have good soil for my trees, roses, and bushes :)
 
Compared to three solid years of recycling soil, I get better results this new way. Just my experience in my environment(s).
 
I hope my excperience can help a little.
 
 
-mrgg
 
 
 
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I think it is fine as long as you are 100% sure your plants didn't have any infestations.
 
I learned late what broad mites were, after I reused soil from a plant affected by it.
 
That is my beginner experience.
 
If you reuse soil I think it's best to leave the previous root ball in the soil and dispose of the plant at ground level and above only
Then I'd plant some clovers on it to keep the soil active through winter which will keep the soil good. If it's a 20L container or above I'd even throw in some worms and throw in the food scraps
 
Disturbing the soil will mess with the microbes and fungi in the soil and if you dig up the whole root system you're probably best starting again as the soil might "die"
 
For what it's worth, yes I do reuse but wait for at least a half year to do it.Think of the days when farmers used to rotate their crops. I'll keep soil from dead or unwanted plants still in their pots and stack them up in a corner of my yard. When I have enough stacked and I decide to do another round of plants I can dump everything out on a big tarp and break things down to see what I might need to add. Always add DE, agricultural lime, composted chicken manure, sometimes cinder or perlite, whatever my favorite fertilizer is at the time, and mix it in real good. Let that sit for a week or 2, then pot up my babies.
Oh yeah, for seedlings and potting up to 1 gallons I always use fresh fox farms ocean forest.
Up from there is my recycled mix.
 
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