Reusing Soil?

Sappning Fellow Stoners

Yes this is a bit of a noob question

right i have done 8 grows and i have changed my soil each time for fresh soil but i done an experiment last time when discarding soil i thought it seems a waste of 30l of soil so i put a weed plant into it and grew it out

so yes i reused soil but i pulled more in yield of that 1 plant in old soil that i pulled out of my 1 plant in fresh soil


nothing was different nothing both plants where on 20.10.10 nutes 2 times a week

reused soil


Fresh Soil



so what im asking from anyone but bmeat


is any ideas as o why the reused soil had a better yield than the fresh?

Edit: both plants where same strain same age

Sorry, I would only be guessing if I came up with a theory on why that occurs, all I know is I'm definitely going to take advantage of your findings. Soil recycling it is!

very interesting!

Hmmm, I guess i'm gonna be reusing soil from now on!

im on no way telling people to reuse soil it may be a massive mistake im just wondering on my findings

if you had a lot of organic materal in the soil maybe it takes awile to get the nutes going a by the second time the plant is getting it plus the nutes your giving it the other thing same kind and time but are they clones from plant ,if not seeds mite vary as people do nice though save people money anyway

nope both plants where from a batch of cuttings taken at the same time and roughly the same size at time of planting

Im a newbie really

But did you train them diffrently? first pic looks like 1 cola, 2nd has 4?

i may just be seeing it wrong, but just a thought

the 1st one for some reason didnt grow 1 big cola it went into 4 bigish ones never done any topping on them as i wanted to just see what happend as far as i remember they both got some LST and that it

i keep soil till it's spent. i amend it each time i use it. so it's not really the same soil. i just pull out all the roots first. ya can't use new soil every time. it's not cost efficient. and as it turns out, unnecessary.

As soil is technically just a medium for the roots to develop in and draw nutrients from, as long as you are using fertilizers then it should be fine to re-use. That said the major worry involved would be one of buildup. Bacteria and salts to name the important ones.
As long as the soil showed no problems before and is given a thorough watering through with plenty of clean water, then there shouldn't be any problems down the line.
A theory on why your second grow may have seemed healthier might lie both in the fact that the soil's natural breakdown process would have been more advanced than the first grow, and the addition of organic material(in the form of old roots from the previous plant)adding to that breakdown process probably doesn't hurt either.
I've always re-used my soil for growing other things like herbs, peppers, and tomatoes, but not for growing more bud. Seems like you did alright by it and that might be enough to help the wallet of some ailing budget growers.

Thumbs up in my opinion. Keep it green. Peace.

The dudes over at skunk mag do this. Basically the amendments break down at different speeds so its not all used up the first time around. I can't remember who it was over there but they had similar results to you. He said he adds amendments as needed but the plants seem happier on the reused than the new. They do TLO overthere. Check it out

As others have said above I don't think there is anything wrong with it as long as you are not carrying insect or disease problems forward. Most good potting mixes are mostly organics which decompose and just get better with time. Toss some volume in the flower bed and replenish with some good fresh stuff.

I just read a little about this and the article basically said that when you grow beneficial microbes form in the soil and it takes a while for them to be really active so by the second grow in the same soil they are in full swing and doing there thing to help your plant

Rosenthal notes that beneficial microbe populations do not reach peak population until the soil has been used 2 to 3 times. I have always reused my soil and without hesitation. I clear all organic matter from the roots out, flush it well and go easy on nutrients on the next plants until they demonstrate a need.

How do you get all the roots out ? Won't they rot ?

harley420 said:

How do you get all the roots out ? Won't they rot ?

Click to expand...

Yes they do rot but as someone said in this post somewhere they ass goodness back into the soil and most roots are removed when i screen the soil

as for the carrying bugs and bit over to my new grows im very OTT on Cleaning my grow room haha

I re-cycle 'most of' my soil...
For use on growing plants, not seedlings, or clones...
First I smell it, if it smells good, then I dont worry, if it smells bad, I toss it...
I dump out all my used soil on a flat surface, mix it and get clumps out...
Spray it lightly with Neem, and maybe some H2O2, and let it sit exposed [in basement], with fan blowing on it to dry it out...
I have this pile of drying used soil, which I use to fill new pots when transplanting...
I like to feel it, and mix it everytime I walk by...
Good luck....