Reusing soil/perlite mix

Hello, I have 4 30 liter plastic pots, in each one 20 liter mix of 15 liter soil and 5 liter perlite (so 75%soil/25%perlite mix). I plan to reuse the 75%soil/25%perlite mix for repotting from smaller, starter pots.

Question #1: is it better to adjust to 50%soil/50%perlite to let the roots grow faster and get a bigger plant?
Question #2: is it better to nute the mix before I repot from the smaller pots?

If you do reuse the soil, be aware of PH issues, as well as excessive/deficient of nutrients. Could have either.
If it’s a somewhat mature plant I would thoroughly water after transplant. If they get stressed, they won’t uptake too much nutrients and get nutrient burn. Give them nutrients when it’s time to water again. @Brooklyn


I agree. 25% perlite is probably enough for just about everyone. Either way putting more perlite in there won’t necessarily make your plants grow bigger or faster. The idea is to just keep your medium from becoming compacted. Nutrients will depend on how/if the soil already contains some ammendments.


If you are interested in making your own soil would be really good to start a compost pile and out all of your old soil in there


I’ve been playing around with re using soil.

I use fox farms ocean forest and happy frog with added perlite. I usually flush my plants before harvest, so the soil is fairly inert after that.

After harvest I put the soil in a bin, rotate for a few weeks, then use to plant my clones. So far it seems to be doing a good job.

For re-potting I think you’d have to start enriching the soil. As mentioned, if you don’t flush the soil it may wreak havoc with pH.


@Drinkslinger… Am I correct in assuming you’re referring to growing in pots? My question: What about an out door grow? I’m using Sub Cool’s Super Soil (1st time growing in ground) and was wondering if I could/should reuse next year what’s in the ground. If so, how? Flush? Dig it all out and compost? Leave it alone and just top-dress? Etc.

Thank you for your help…


I’ll be honest. I don’t know. I’ve always grown in containers.

I wish I could grow in the ground.

This is my 4th year in ground in greenhouse. I do a combination, I compost, and I have 50yr.old pile of barnyard manure. Every year I roll it all over the best I can by hand. Greenhouse is 6x10x8.5H, with 7 plants, 4 have hit 8ft.!


Thank you @Caraboo… This helps. Anyone else? I would like for others with experience in this area to please share their knowledge and wisdom. Thank you all.

I do reuse my soil and add fresh new soil and perlite, blood and bone meal and cow manure. No probs yet. My pots are 15 gal.

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Thank you @PinkFlight 4 D help. Does anyone else have experience with doing this “in the ground”? Thanx again… :smiley:

Hi CBDbudMan…how much soil are you trying to retrieve? In all my years of general gardening,I have never tried to salvage soil from the ground, but rather, add to it. Can plant a cover crop of nitrogen-rich clover to keep soil intact. Can add microbes and worms and humics and compost and coffee grounds, and have your own super soil for next year’s grow. Add some good hot cow manure before you plant, and your new super soil is better than ever. Bagging up dirt for storage you run the risk of keeping something you don’t want on your new grow next year. Like Spider Mites…

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Hello @PinkFlight. You have some wonderful insights. The 6 holes I dug are about 20 gals each, to give you an idea of the amount of soil that’s in question here. I guess where I’m coming from is that, when people talk about super soil, the recipe always starts off with new bags of soil and a list of things to amend it with.

So, instead of buying new bags of soil every year, I thought that I could use what’s left and build it up using the same list of amendments as new super soil, just not new bags of base soil. I am looking for a way to save some cash withOUT shorting my plants in any way. So, you’re saying, just leave the soil in the ground and amend it there. Do I have that right?

Again, thanx for your help… :smiley:

Yes, CBDbudMan. That’s all you can really do…can also cover it up with plastic. Just turn it in the spring a couple of times and I bet your soil is hotter than ever after you add your amendments.

Thank you @PinkFlight for all of your info/help. Same goes for everyone else that has contributed.

I appreciate you all. :+1: