Soils

[The Grass Baas]

Hey guys

So I've been reading up about soils and it's all really abit too much to be honest. I have grown in a +-60L fabric pot with soil that I bought from builders. Their "organic" potting soils. I think it's a grandmaster brand or something. Either way. I used 1x 60dm3 bag and the only nutes I ever gave were some nitrogen fertilizer. Gave it a teaspoon with water once every 2 or 3 weeks in veg and then some freedom farms fire juice once every week at 2ml or 3ml. From this I flushed for about a week or so using just my normal tap water that it's always been given (don't know the ph). I would pour quite abit of water so that it drains out the bottom quite abit everytime, but allowing it to dry over the next day or two. 

So basically what I'm looking to find out is wether I am able to reuse soil in an indoor grow. For example. I have 6x 20l flowering pots. Would I be able to reuse that soil after a harvest to transfer some vegging plants into as the base? Should I just add abit more and till it abit? Any extra nutes before I use it again etc etc. Plus I'm looking to find out what's the best options for me in PTA cbd area.? 

Any help will be appreciated. Thank you

[CreX]

Yea man! Ofcoarse you can reuse your grow meduim! 

But I would maybe buy a new cycle of soil if you want and put your used soil in a pile and re-ammend them with various things. 

Let it sit for a the whole grow, and then you could use it for your next grow, doing the same with your newer soil. 

@SkunkPharm knows his shit, maybe he can help out

[The Grass Baas]

@CreX Aah dude Thanks man. That's what I'm kind of looking to do. That actually makes sense to cycle it like that. Appreciate it.

[SkunkPharm]

You can re~use your soil. In the US the guys would test their soil after every grow and re~amend accordingly. On the scale that we grow I dont think it makes sence. 

I would find a good quality compost(vermicompost) and add some kelp meal and basalt rock dust(turbogrow). Maybe some alfalfa meal as atop dressing. You really only need to amend your soil once a year or every second grow. 

All my 50~70l bags have got something else growing in them atm. 

[Popcoen]

@Saurus Basically you can, but you want to sterilize it in the oven (bake it for like 20mins) to kill any spores, bacteria and insects etc. (this is personal preferance but you can just use it if you think the soils 100s) so you know the soil would be perfect for an indoor grow and then just mix it with a trusted fertilizer! This works well and with indoor just dechlorinate your water and test the ph to get the most out of your soil and plants! 
you can amend it aswell if you feel that the fertilizer isn’t sufficient enough! 
good luck growing brother!!

[420SA]

I've had good results reusing my living soil without feeding. I didn't re-amend as well... but it depends on the soil of course

@SkunkPharm is spot on

[SkunkPharm]

1 minute ago, Popcoen said:

@Saurus Basically you can, but you want to sterilize it in the oven (bake it for like 20mins) to kill any spores, bacteria and insects etc. (this is personal preferance but you can just use it if you think the soils 100s) so you know the soil would be perfect for an indoor grow and then just mix it with a trusted fertilizer! This works well and with indoor just dechlorinate your water and test the ph to get the most out of your soil and plants! 
you can amend it aswell if you feel that the fertilizer isn’t sufficient enough! 
good luck growing brother!!

I don't agree with you on this statement. If you grow organicly why would you destroy all the micro organism that you worked so hard cultivating during the season? I use organic cultivation methods indoors and you must manage the pests accordngly by having an IPM system. 

[420SA]

2 minutes ago, Popcoen said:

@Saurus Basically you can, but you want to sterilize it in the oven (bake it for like 20mins) to kill any spores, bacteria and insects etc. (this is personal preferance but you can just use it if you think the soils 100s) so you know the soil would be perfect for an indoor grow and then just mix it with a trusted fertilizer! This works well and with indoor just dechlorinate your water and test the ph to get the most out of your soil and plants! 
you can amend it aswell if you feel that the fertilizer isn’t sufficient enough! 
good luck growing brother!!

Controversial one that... sterilizing an organic soil is the last thing I would suggest to be honest. I would rather suggest using an IPM to control any pests or bad fungus. 

Depends on your preferences of course but personally I feel sterilizing the soil is setting you back

[420SA]

Took the words out my post there Skunk lol

[Popcoen]

@420SA to be honest I don’t use garden soil, I buy organic soil and use that, been wary of using outdoor soil indoors yah know? 
But agreed all comes down to preference! 

[420SA]

3 minutes ago, SkunkPharm said:

I don't agree with you on this statement. If you grow organicly why would you destroy all the micro organism that you worked so hard cultivating during the season? I use organic cultivation methods indoors and you must manage the pests accordngly by having an IPM system. 

I've found that my re-used soil seems even more alive than the initial soil. Like you say the micro-organisms cultivate as you let the used soil sit. I take all my used soil, throw it all together in a semi open container outside, chuck in a few earthworms and let nature do its wonder work

[Popcoen]

@420SA I’ll actually give this a shot... will save on buying soil regularly. 

[420SA]

4 minutes ago, Popcoen said:

@420SA to be honest I don’t use garden soil, I buy organic soil and use that, been wary of using outdoor soil indoors yah know? 
But agreed all comes down to preference! 

When you say garden soil I assume you mean garden master, culterra and all that shite. By all means don't use that soil. You won't find a good soil for cannabis at most nurseries or builders warehouse. You'll need to look to a grow shop for a commercially available soil for cannabis, that works. 

I mix my own and every grower should have a crack at mixing their own soil at some time in their growing. You may find yourself not turning back

[Popcoen]

@420SA Ive honestly bee using Just Cannabis soil for my grows and its worked like a bomb, but what i think im going to try is after harvesting keeping the soil and let it sit and just feed the micro organisms that have been built, 

 

Thanks for the additional info @420SA and @SkunkPharm! Always learning something new 

[SkunkPharm]

I have seen really good results with Just Cannabis soil. I have seen the pics of the owners grow this last season. Very impressed. Will be testing it myself on yhe next autoflower run.

[Popcoen]

@SkunkPharm I honestly think you will love it, i use it with smart fabric pots so there is a lot of fresh air constantly flowing through the roots because of the pots and the coconut husk in the soil! 

[CreX]

I bought a bag last year sometime, but I mixed it out into more garden soils. 

I noticed quite a lot of slow release ferts in it that, as you said @SkunkPharm, might take a few grows to fully consume 

[SkunkPharm]

I also do the smartpot thing. But have been using peat moss in my soil mixes of late. I love the peat as it retains about double the amount of water and it reduces the need to water often in the veg cycle. 

[Popcoen]

@SkunkPharm What brand peat moss do you use? Ive read up about it curious to see how it would work

[SkunkPharm]

2 minutes ago, Popcoen said:

@SkunkPharm What brand peat moss do you use? Ive read up about it curious to see how it would work

The first one I used was the Klasmann-Deilmann Lithuanian Peat Moss. And now recently I bought the Kekkilä Peat. Please dont pay more than R400 for a bale. If you dont want to use that much and want to use it I have some left over, if you are in cape towns Northen Suburbs. When you use peat you also have to buffer it with some lime and/or gypsum as the pH is low.

[The Grass Baas]

@SkunkPharm Howzit man. Thanks so much for the response.

 

The information is great. 

I will for starters maybe buy 2 batches of proper soil that I can then cycle each grow. Appreciate it.

[420SA]

3 hours ago, SkunkPharm said:

I also do the smartpot thing. But have been using peat moss in my soil mixes of late. I love the peat as it retains about double the amount of water and it reduces the need to water often in the veg cycle. 

True that. Once it dries though its damn hard to get wet, very hydrophobic initially. Have you found that? Not a big deal but something to consider if your soil has dried out. When trying to water the dry soil it can lead to pockets of soil staying completely dry. So best not let the soil dry out, which you shouldn't do anyway

[SkunkPharm]

16 minutes ago, 420SA said:

True that. Once it dries though its damn hard to get wet, very hydrophobic initially. Have you found that? Not a big deal but something to consider if your soil has dried out. When trying to water the dry soil it can lead to pockets of soil staying completely dry. So best not let the soil dry out, which you shouldn't do anyway

I aggree. It does become hydrophobic. When the plant starts using more water like in the 1st 5 or 6 weeks of flower I water daily. But it all comes down to watching what your plants are doing and the size of your pots. 

[oldsandals]

My organic soil mix, developed over about 10 years of side by side tests. I'm from KZN so the sources are found closest to me here that I have added. 

 

Per 1000 litres mix you will need the following core ingredients:

400 litres of flushed expanded coco coir. Always flush more than you think you need to... (coco helps with the cation exchange capacity and adds a sponge effect to the medium allowing moisture to be spread out more equally, i use this coco)

300 litres of perlite. (along with the coco this is the main source of storing oxygen in the medium, i get mine from here or here)

150 litres of quality moist black worm castings. (The main component of the nutrients for the mix come from the worm castings, it is broad spectrum NPK and micronutrients, i get mine from here or here)

150 litres of quality compost. (if contains manure - use only 20% or lower manure content, can be mushroom compost or wood chips + manure etc. i get mine from here)

 

Per 1000 litres mix you will need the following amendments:

500g of Talbourne Organics 2-3-2 (I use this as the main source of phosphorous instead of bone meal but it has all NPK and micro nutrients also. Very good product. Get the non pelleted version, their website)

2kg of Dolomite lime (main source of calcium and magnesium while also stabilizing pH, can get it at most nurseries or garden shops)

1kg of Rock dust (Turbo grow - source of micro nutrients)

1kg of Diatomaceous earth (the silica breaks down over time adding strength to plant cell structures, making stems stronger and leaves glossy. i get mine here)

200g of Cricket frass (contains high amount of calcium carbonate and iron, i get mine here)

 

Liquid feeds that work well with this mix:

Fish emulsion (Seagro brand has very low pH which is useful to bring down tap water that is higher than 6.5pH)

Seaweed extract (The auxins and cytokinins help to de-stress plants and give life back to stunted or shocked plants, can increase internode lengths and delay onset of flowering)

Biobizz bloom (I don't really use this anymore but can be useful to boost flowering plants without adding nitrogen)

Biobizz grow (contains mostly fermented sugar beets and molasses, good to feed the soil microbes in light dilutions)

Biobizz fish mix (pH corrected fish emulsion with molasses, I prefer to use the Seagro brand for the acidity)

 

This mix is not a super soil so depending on the container or hole size that you use for a single plant, you may need to add liquid feed after 4-5 weeks of growth to support hungry plants, but you will be not adding much since majority of the nutrients are in the soil. Keeping the pH between 5.9 and 6.6 seems to have best results. Feed plants only plain water for about three weeks prior to harvest for the cleanest best tasting end product. 

 

Edit: to answer OP's question of reusing soil. I think that a proper made organic soil gets better over time because the larger particle sizes are broken down over time by the microbes and are more available to the plant for uptake. But I generally do add a bit of worm castings + dolomite lime + talbourne 2-3-2 for reusing the same soil that has grown plants in already, guessing how much is a bit of an art. My soil that I am using now has been grown in about 10 times and still very good. 

Edited June 19, 2020 by oldsandals

[Popcoen]

@SkunkPharm Ah i appreciate that offer bro... unfortunately im from Joburg, But thanks for the advice!