Organic Soil Mix Recipe

[ColaCalyx]

This recipe gives you a well-draining mix perfect for container gardening, and is easily customized. It's based on amendments per gallon, making it easy to mix small amounts for indoor soil growers.

Here's a recipe based on volume:
5 parts CSPM or 50%
3 parts perlite or 30%
2 parts compost/vermicompost or 20%

I eyeball these measurements with a 5 gallon bucket.

Fertilizer:
Add 1/4 C. dry meal fertilizer per gallon (Kelp, alfalfa, neem, chicken manure pellets, etc)
- Check out my post on how to make a customizable dry meal mix for topdressing: Topdressing dry meals: easy way to create your own dry fertilizer mix, and adjust NPK

Lime and minerals per gallon of base mix:
1 Tbsp calcium carbonate (gardening lime, ag lime, oyster shell) or dolomite lime
1 Tbsp rock dust
1 Tbsp greensand (Optional)

Leave out the fertilizer, rock dust, and greensand and you'll have a fine seedling mix.

 

[ColaCalyx]

Gypsum is also a useful addition to the above recipe at 1 Tbsp per gallon

 

[bobrown14]

I use similar soil mix but add in a cup of malted barley ground fine and some bio-char.

Racoons like the malted barley so if they are an issue leave it out for outdoor grow.

 

[ColaCalyx]

I use similar soil mix but add in a cup of malted barley ground fine and some bio-char.

Racoons like the malted barley so if they are an issue leave it out for outdoor grow.

Yes, I'm sure to add a source of chitin and enzymes in the soil or at least in the topdresses. Just went through my last bit of malted barley and corn, time for a refill. I ditched the cover crop of clover this year in favor of a thick layer of wheat straw. Let's just say, I'm getting used to how much less I have to water. Way more worms with the straw, and damn it breaks down quick, worms are flippin. I tried looking up how much chitin is contained in straw, didn't get a distinct answer - but it's there.
As for the biochar, I like it, but I think of it as an extra....plus it costs. I've used hardwood charcoal before to cut the cost, and it worked OK, just doesn't have the same porosity and uniform size I want.

 

[Stunger]

I can't find any insect frass or crab shell meal for Chitin. I am thinking of buying some packets of crushed dried shrimps from an Asian food shop which have salt added, which I presume soaking/washing it thru with clean water half a dozen times should hopefully remove the salt and then I can reamend my container soil and allow a 3 month cook/rest before growing in it. I didn't realize Chitin was in straw. I have already got bio-char in my soil.

 

[ColaCalyx]

I can't find any insect frass or crab shell meal for Chitin. I am thinking of buying some packets of crushed dried shrimps from an Asian food shop which have salt added, which I presume soaking/washing it thru with clean water half a dozen times should hopefully remove the salt and then I can reamend my container soil and allow a 3 month cook/rest before growing in it. I didn't realize Chitin was in straw. I have already got bio-char in my soil.

As bobrown14 mentioned, he uses malted barley powder as a chitin source, this is widely available online or at a local brewery store. Another seconday source can actually be insects themselves. I know a grower who collects the bugs from his zapper, and mixes them into the soil. This will promote the chitin-eating bacteria.
I wouldn't recommend the source you mentioned, I think it will be safer if you just buy some shrimp with the shells and cook the shells in the oven until dried out, then grind them fine. Don't worry about the heat you use, chitin is stable to heat in the neighborhood of 380 C/ 716 F!

 

[Stunger]

As bobrown14 mentioned, he uses malted barley powder as a chitin source, this is widely available online or at a local brewery store.

I must have missed that. I was thinking he was specifically adding in Crustacean meal for purposes of Chitin, that the malted barley was more for the micro herd. Either way the addition Chitin sounds very beneficial. I have some mussel/salmon meal and mussel/oyster flour in my mix but I don't think that is a Chitin source?

 

[ColaCalyx]

I must have missed that. I was thinking he was specifically adding in Crustacean meal for purposes of Chitin, that the malted barley was more for the micro herd. Either way the addition Chitin sounds very beneficial. I have some mussel/salmon meal and mussel/oyster flour in my mix but I don't think that is a Chitin source?

True, he didn't specifically mention MBP as a chitin source - but it is.
Yeah, the fish/shellfish meal isn't a source for chitin. You'll want the bug-like sea creatures (lobster, crab, prawns).

 

[bobrown14]

Yes, I'm sure to add a source of chitin and enzymes in the soil or at least in the topdresses. Just went through my last bit of malted barley and corn, time for a refill. I ditched the cover crop of clover this year in favor of a thick layer of wheat straw. Let's just say, I'm getting used to how much less I have to water. Way more worms with the straw, and damn it breaks down quick, worms are flippin. I tried looking up how much chitin is contained in straw, didn't get a distinct answer - but it's there.
As for the biochar, I like it, but I think of it as an extra....plus it costs. I've used hardwood charcoal before to cut the cost, and it worked OK, just doesn't have the same porosity and uniform size I want.

I can't find any insect frass or crab shell meal for Chitin. I am thinking of buying some packets of crushed dried shrimps from an Asian food shop which have salt added, which I presume soaking/washing it thru with clean water half a dozen times should hopefully remove the salt and then I can reamend my container soil and allow a 3 month cook/rest before growing in it. I didn't realize Chitin was in straw. I have already got bio-char in my soil.

Crustacean meal works.

If you compost your kitchen scraps outside you will see rollie pollies in the compost eventually. They will turn out in large numbers. They are the only land crustacean so they break down to chitten and other goodies in your vermi-compost.
Malted barley is another great source.

Here's some home made bio-char. Once the rain washes the ashes off this is what's left. All hardwood as fuel. Mostly birch in this one.