New Grower How often should the soil be replaced after growing indoors in it?

[DG59]

I try not to but if I am low on soil and can't go to town because I have "partaken some of the last grow" LOL I will use some. Dirt is cheap so I normally buy new and put the old on my compost pile.

 

[TimeTraveler]

It certainly seems to be possible to re-use non-organic soil, but it seems fiddlier due to the nature of salt buildup and so on.

Organic can be a little more pricey up front (CAN BE, pop22 is running a thread to show how to grow full organic on the cheap), but it can pay for itself over time because it tends to actually benefit from being recycled: the soil microbiology gets stronger and healthier over time, and many report they get better results over the years. I've got a full organic garden in addition to an indoor setup, and the nutes and mixes I bought will last me a LONG time, and once I add a worm farm and compost heap I'll rarely have to pay for anything anymore.

 

[bartlancertp]

I mix 50% old with 50% new soil and put this in the bottom 1/3 of the pot, then new soil on top. I use GH Floranova nutrients.

 

[pop22]

soil doesn't wear out and it is always breaking down, making more nutrients available. What it does need is to have bulk returned to it. As soil particles break down and get smaller and smaller, there becomes less airspaces. Mixing it with coco coir, humus, etc gives volume, airspaces and lets the old soil become more of a nutrient source. Clay is just soil broken down super fine and is actually nutrient rich, but its so compacted that it has no airspaces for roots and microbes to live in.

I'm finding coco is a great medium for refreshing recycled soil. I think its better than peat for building back your soil sturcture and its renewable.

 

[TimeTraveler]

soil doesn't wear out and it is always breaking down, making more nutrients available. What it does need is to have bulk returned to it. As soil particles break down and get smaller and smaller, there becomes less airspaces. Mixing it with coco coir, humus, etc gives volume, airspaces and lets the old soil become more of a nutrient source. Clay is just soil broken down super fine and is actually nutrient rich, but its so compacted that it has no airspaces for roots and microbes to live in.

I'm finding coco is a great medium for refreshing recycled soil. I think its better than peat for building back your soil sturcture and its renewable.

Agreed; I used coco in my current soil instead of peat, and it's working wonderfully. As it breaks down I intend to keep adding coco coir to keep it properly aerated.

 

[pop22]

But what about soil that has been used for a non-organic grow but with plain mineral based nutes? I have never cared to try and re-use it in fear of messing up a plant with build up salts or the loss of proper buffering capabilities. Also if you don't grow organic isn't there a risk of the roots left behind from the prior grow starting to rot in the soil?
Am I correct in presuming this or can you re-use non-organically grown soil. I haven't really found people on the net doing this so I think it's better not to re-use soil unless you go organic.

start a worm farm, feed them your rootballs! I chop them up into chunks and toss them in the bin. they take 3-6 months to be all digested, but thats a lot faster than trying to compost them any other way and the microbes breakdown left over nutes into a usable form. Compost worms are amazing!

 

[Reedroguez]

I'll have to take a look into that, thanks.