Soil Mix for outdoor, 300 gal aeropot:

[MrTwister]

I'm changing my soil mix based on cost and performance. My initial mix was as follows (not including oyster shell powder and such, just the bulk volume):

*this is intended for a lot of compost tea innoculation

Base Mix (25%):
Earth Worm Castings 12.5%
Compost 12.5%

Amendments (75%):
Coco Coir 32%
Peat moss 20.5%
Pumice 7.5%
Vermaculite 7.5%
Perlite 7.5%

Now I'm trying to figure if i can just substitute peat for coco and pumice, vermaculite, and perlite for rice hulls. The result would be as follows:

Base Mix (25%):
Earth Worm Castings 12.5%
Compost 12.5%

Amendments (75%)
Coco Coir 52.5%
Rice Hulls 22.5%

How does this look? Any thoughts that come to your head would be useful to me.

 

[saner1r]

I like the mix you have posted. I would ask you in the amendments (75%) what is in the amender?

I also mix my own soil and have been for some time now. I believe that you should load it up with everything you need to have that plant finish. I mean load the soil mixture with everything you need from veg to flower! "Dry Ingredients". I any add tea during the from veg to flower and then use tea before the finish.

 

[Seamaiden]

I'm changing my soil mix based on cost and performance. My initial mix was as follows (not including oyster shell powder and such, just the bulk volume):

*this is intended for a lot of compost tea innoculation

Base Mix (25%):
Earth Worm Castings 12.5%
Compost 12.5%

Amendments (75%):
Coco Coir 32%
Peat moss 20.5%
Pumice 7.5%
Vermaculite 7.5%
Perlite 7.5%

Now I'm trying to figure if i can just substitute peat for coco and pumice, vermaculite, and perlite for rice hulls. The result would be as follows:

Base Mix (25%):
Earth Worm Castings 12.5%
Compost 12.5%

Amendments (75%)
Coco Coir 52.5%
Rice Hulls 22.5%

How does this look? Any thoughts that come to your head would be useful to me.

:evilgrin0040: Sorry, me no likey. Your mix just doesn't quite qualify as soil to me. Why the coco coir? Worm casting and compost ratios are equal, I personally prefer much more compost dominance there. Besides, once the mix gets going you'll have worms in there already, no need to add in more castings.

I detest vermiculite more than perlite. Vermiculite holds onto water, though, so if you're in an area where you run the risk of the pots drying out too quickly, then I think it should be added. Rice hulls swap out equally for perlite, IMO, and perlite doesn't even need to be present in a good mix in the first place.

Once amendment surpass 'base' then they are no longer merely amendments, they become the whole ball of wax. What are the amendments?

I would also ditch the peat moss. Rice hulls can really do a good job of lightening up the mix, where castings will make it more dense, as will vermiculite and peat. I would add sand to that mix, m'self. You wouldn't really need to use silicate sands with the hulls.

If your goal is to improve performance, then focus on soil and compost, make the 'amendments' equal far less of the total mix than soil. Right now your amounts appear upside down to me with amendments (NOW I see what you're saying there! sorry) comprising the majority of the mix instead of well-mineralized, good quality soil that will do a better job housing soil food web organisms than either peat or coco coir will.

Also, by adding coco coir in such significant amounts you're creating a new set of problems for yourself, in my opinion.

 

[MrTwister]

:evilgrin0040: Sorry, me no likey. Your mix just doesn't quite qualify as soil to me. Why the coco coir? Worm casting and compost ratios are equal, I personally prefer much more compost dominance there. Besides, once the mix gets going you'll have worms in there already, no need to add in more castings.

I detest vermiculite more than perlite. Vermiculite holds onto water, though, so if you're in an area where you run the risk of the pots drying out too quickly, then I think it should be added. Rice hulls swap out equally for perlite, IMO, and perlite doesn't even need to be present in a good mix in the first place.

Once amendment surpass 'base' then they are no longer merely amendments, they become the whole ball of wax. What are the amendments?

I would also ditch the peat moss. Rice hulls can really do a good job of lightening up the mix, where castings will make it more dense, as will vermiculite and peat. I would add sand to that mix, m'self. You wouldn't really need to use silicate sands with the hulls.

If your goal is to improve performance, then focus on soil and compost, make the 'amendments' equal far less of the total mix than soil. Right now your amounts appear upside down to me with amendments (NOW I see what you're saying there! sorry) comprising the majority of the mix instead of well-mineralized, good quality soil that will do a better job housing soil food web organisms than either peat or coco coir will.

Also, by adding coco coir in such significant amounts you're creating a new set of problems for yourself, in my opinion.

Thanks for the replies! I'm not sure how my formulary migrated to be what it is now. For one I got positive feedback on the "original" mix from a lot of locals who are major teamakers. It's definitely a pro-tea mix where tea is going to be loaded on every other day. We are not using the "load it up with what it needs" paradigm because the lead horticulturalist is well established with his methods on a smaller scale and the flushing/finishing is what allows us to sell this stuff to the top collectives- smooth as butter. The gardeners here are giving all creative control to the top performer so I can only defend the product quality and have faith in the method. The light soil mix only serves as a home for bacterial and fungal growth. We have endless water supply so it's a heavy drainer "starve 'em and stuff 'em" watering. It's certainly not a drip operation.

Yes i've seen 10 pounders come out of the bat shit chicken shit cow shit method but this is not the direction we're taking it. I'm NO AUTHORITY on the subject obviously but I would like to know how you would personally improve on it.

Oh and the EWC are about 10 fold the price of rice hulls, coco, and 8 fold the price of compost.

Does pumice have a purpose here?

I realize that the "base mix" is only 25% so it's hardly a "base mix" but this is sortof what we're calling it. We bought all EWC in the county this year-- funny since it's Humboldt county. Sorry guys :)

edit: oh yeah what wuold you line the bottom of these with? I was thinking pumice but i have read perlite and gravel. Opinions welcome.

Thanks for the replies by the way! I usually don't get much response -- stupid questions maybe? - i try to contribute and i think i have some knowledge but i'm trying to get some feedback on the soil thing because i see so many options.

 

[Seamaiden]

Hhmm.. not stupid questions, in my opinion. My beds all started with good top-soil, raised beds are what I'm working with because my "soil" is mostly clay and rock and I can't work it, physically speaking. I did use some chicken poop in the beginning, and I think some bat shit, but it's not the entire foundation on which my own organic soil is built. Not saying I'm an expert, but it's not what I personally would use unless I understood better how to work with something that doesn't appear to be mineralized soil exactly as though it were soil.

Pumice would provide certain minerals, as well as hopefully stabilizing and increasing CEC. I have to assume that what it can provide depends as much on source rock as available microbes, etc, that can process what's available in that rock.

Coco, interestingly enough, has an awesome CEC, but it locks onto two important minerals--calcium and magnesium--that can make it difficult to work with. For that, I personally would go with oyster shell flour (or hell, even shells, they'll break down eventually) or dolomitic lime, but more would probably have to be added during the course of the season and to the initial mix to make up for the coco's tendencies. Once nice thing about coco here would be the fact that it's naturally high in K. It's the significant percentage of coco and peat in the mix that have my head a little boggled about, to my mind those make it qualify as a soilless mix.

Anyway, I haven't spent much time changing my mix up because there is no way I'm digging out that planter and I haven't yet filled up my Smart Pots. I just went with what would be the easiest method to work with should I not be able to physically give care to plants. If missing elements and food in this mix would be made up frequently through the course of the season, then I'm interested in seeing how it performs, especially if comparisons are made in the same garden(s) with this mix and maybe another mix.

 

[MrTwister]

Well... I spoke with some people and decided to go with the original formula with just the rice hulls substituted in for the perlite.

the peat moss is supposed to be a good medium for beneficial fungus which makes sense because people complain about it being a good place for bad fungus as well.

also, the vermiculite and pumice are present in some of the best mixes and it isn't the cheapest part; on the contrary.. so it stands to reason that it is good... i guess. truckloads of this stuff... arghh....