Build A Soil From Scratch in 2 Simple Steps March 10 2015, 128 Comments

Build A Soil From Scratch in 2 Simple Steps....

And Have The Best Grow Of Your Life!

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Have you ever thought about how a bagged soil company settles on a recipe? What about where they get the ingredients from? Can you trust the soil companies?

There are so many soil products on the market and most manufacturers are getting all the same ingredients from the same sources and getting them bagged all at the same facilities. All that changes is the label and exact ingredients used. There is little regulation in the industry and the only approval for a Label is if you are citing NPK numbers or fertilizer claims. Besides that, you can list your most expensive and attractive ingredient First on the label even if that ingredient happens to be in the lowest concentration in the soil. This allows companies to list ingredients that sound incredible but then fail to back them up with actual quantities used. Then as a soil company gets larger they have to buy in large scale and start looking to the most affordable sources for ingredients such as, City Waste, Bio-Solids, Poultry Waste, Cattle Waste. Think like a big company for a minute and compare bagged soil to our food industry but with less regulation, then you can see how weird the situation truly is. Thankfully there are a number of decent potting soils on the market but none will compare to making your own from scratch.

So, let’s say you have decided to make your own soil from scratch and are willing to do whatever it takes to make the best. Well, where do you start? There are so many recipes out there!!!

There is so much talk online in the organic forums about creating an ideal soil. Many different recipes from many different growers. Some claiming their soil is the best, others indicating that you should use spikes of nutrients and layers of different soil. It's challenging as a new grower to actually decide on a recipe and then stick to it. One of the many things that growers do when using bottled nutrients, is change nutrient brands all the time. Usually looking for the ultimate grow product that will finally allow them to purchase a good grow. This mentality usually wears off after a few runs but it's important not to start that mind set all over again in organics. If you are brand new, start to learn why each ingredient is added to a mix. Once you have that understanding you can easily make a mix from scratch from components that you have available locally or regionally depending on your budget.

All Credit for recipe to Clackamas Coots

Step #1: Design The Base Mix Ratios.

This is benchmark to use at first and then start tweaking based on your situation.


This means that there are 3 main components at 1 part each.

Example: To make 15 gallons of soil. 1 Part would be 5 gallons.

1 Part Sphagnum Peatmoss, Coco Coir, Leaf-mold, Etc.
1 Part Aeration material like lava rock, pumice, perlite, rice hulls etc.
1 Part Vermicompost or plain compost.

The recipe that I prefer is a little more complicated and is as follows.

40% Sphagnum Peat Moss
25% Vermicompost
20% Pumice
15% Par Boiled Rice Hulls

You’ll notice that if you combine the rice hulls and pumice it’s basically a 1:1:1 mix with just a little less vermicompost as I like to top-dress with more.

Step #2: Adding The Minerals & Nutrients:

Consider each ingredient and why it's being added. Also consider that many organic approved products just aren't as good as others. The top ingredients that are popular that most organic growers avoid are as follows: Blood meal, bone meal, guano, soy, cotton, corn and many other soil conditioners that come from potential GMO crops etc.

A brief explanation of using Cubic Feet as a measurement: Most soil companies sell their soil by the Cubic Foot as do we. But there is a big difference between what constitutes a Cubic Foot. When looking up the Volume for a “DRY” cubic foot in gallons you’ll find 6.4285 gallons. But when looking up the “Liquid” volume for a Cubic Foot you’ll find 7.4805 gallons. Well you won’t be surprised to find that most home gardeners use 7.5 gallons as a cubic foot but most soil companies use 6.4285 gallons per cubic foot. This will explain why you have less soil in some bags than others from two different companies. To be clear, we use 7.5 Gallons at for all of our soil bagging and measurements for addition of amendments.

Here is a recipe that has been proven with soil testing at labs to have a very ideal ratio of nutrients and minerals.

1/2 Cup per cubic foot the following:

* Neem Cake and/or Karanja Cake (NPK, Micro Nutrients and reported Bug Defense all in one)
* Kelp Meal (NPK, Micro Nutrients, Growth Hormones and many other benefits)
* Crustacean Meal (Crab and/or Shrimp Meal) (Calcium, Nitrogen and Chitin along with other benefits)

4 Cups per cubic foot of a mineral mix:

1 Cups Glacial Rock Dust (diverse assortment of minerals)
1 Cup Gypsum (Calcium and Sulfur)
1 Cup Oyster Shell Flour (Very available Calcium to help buffer PH of the Peatmoss)
1 Cup Basalt (Paramagnetic Rock Dust from lava flow that is high in micronutrients)

The Nutrients added above cover all the NPK and all the micronutrients and I could explain why each ingredient is added all day long, but I encourage you to do your own research.

Now let’s say that you had access to a range of Fertilizer amendments to use, which ones should you choose? I like to choose the best product and also the most economical. For instance Guano is really expensive and typically only brings one or two things to the table. Where as Kelp Meal is fairly affordable and brings every nutrient and micronutrient with it along with growth hormones and other secondary benefits. Would it be better to eat Red meat all day long or maybe a little fish protein with some vegetable protein? Same for your soil! No need to get all crazy with Blood meal when we can use, Crustacean, Neem, Fish etc. and all of the ingredients I just mentioned bring tons of secondary benefits where as the Blood Meal only brings Nitrogen and some salt.

Note: If you only have access to Blood Meal, you will be fine and can totally use it, I’m not trying to get on a high horse and look down on people that use these ingredients. I’m only hoping to give reasons to look for better ingredients when those choices are available and providing some reasons for those that want them. All in all, I’d rather see a Blood, Bone and Guano Mix over a synthetic nutrient grow all day long.... but if you start looking into the environmental impact of some of the ingredients we use you’ll quickly consider making your own soil from totally local ingredients and once you have an idea how well this recipe performs you can start tweaking it to use what is available in your region.

Some Recommendations for custom soil building:

MORE isn’t always better. Consider the Kelp, Crustacean and Neem Fertilizers that I recently recommended. Suppose a hypothetical situation where they all take exactly 6 months to be completely broken down in the soil and offer little to no benefit to the plant any longer. Well, adding twice the amount will still lead to a depletion in 6 months... it’s not like having twice the kelp will last twice as long, much better to top dress some a little later or incorporate into teas.

Most soil recipes have a total of 1.5 - 3 cups of Total fertilizers added per cubic foot of Mix. I like to keep things really minimal knowing I can always add more later and topdressing is so easy when you pre-mix with vermicompost. No worry about burning. The other reason I like to add small amounts of simple ingredients is because it allows you to diversify the soil with ingredients you haven’t added later on. For instance, my recipe doesn’t call for Alfalfa, but I love the stuff and make tea’s with it all the time, no reason to have it in the soil and in the tea. But if you never want to brew teas you could always top dress. It’s up to you.

Take it to the next level with Home made Vermicompost and you’ll have a soil better than 99% of the growers out there. Here is an excellent recipe from the guy who really got my brain thinking, Clackamas Coots:

“This is the compost that I started with:
1 c.y. organic barley straw
12 lbs. basalt rock dust
2 c.f. roughly chopped Comfrey as the Nitrogen source
5 c.f. pumice (1/4" size)

When the material ramped back down to 100F or so I added the following:
3 lbs. kelp meal 3 lbs. a neem / karanja meal mix that I had made because I was bored - obviously 1 lb. organic alfalfa meal 1 c.f. roughly chopped Comfrey leaves 1 c.f. roughly chopped mint mix - Peppermint, Spearmint, Thyme, Cilantro, Holy Basil (Tulsi) and chopped Rosemary 3 lbs. organic fish meal 3 lbs. crustacean meal
I loaded this into #150 SmartPot and dumped about 3 gallons of worms that I harvested from other set-ups also using SmartPots. Basically 3 gallons is somewhere around 10 - 11 lbs. of worms. I covered this with barley straw to reduce evaporation in the bedding material.
A year later I harvested over 28 lbs. of worms, thousands and thousands of cocoons (using a 1/8" screen which will capture the cocoons) and this specific batch of vermicompost is what I'm currently using.
It's all about patience - it takes time to create premium humus.
Dat's it!

Then just mix it up as such:
1/3 Humus 1/3 SPM or Leaf Mold 1/3 Aeration (Rice hulls/Pumice/Lava Rock)
A bit of time and effort is required at the front end for sure. After that's done, just add water.”

Mixing the soil together: Recipe for about 18 Cubic Feet of soil or 135 Gallons.

I like to use a big tarp when making soil by hand.

(1) 3.8 Cubic Foot Bale of Sphagnum Peat moss will expand to about 6 cubic feet when opened up. That means that you could make about 15-18 cubic feet of soil with one 3.8 cubic foot bale of peatmoss depending on your final percentages.

I like to break up the peat moss into a flat thick layer on the tarp and then dump the castings on top of that. Then dump all the minerals and fertilizers on top of that followed by your aeration amendments and mix thoroughly. Every once in awhile I take the edge of the tarp and flip the soil back to the middle and keep mixing.... sometimes I move the soil from the left side of the tarp over to the right side of the tarp and then back to the middle just to make sure it’s all mixed well. All in all, don’t get to freaked out about things being mixed exact because it’s all organic and very forgiving.

Once your soil is mixed up, you can plant immediately into it and add a compost tea to kick start the process. With that being said, it always works a little better if you let the soil sit in a big pile to homogenize or “Cook.” Without the use of Bloods, Bones and Guano’s it shouldn’t burn any plants but will be ready to use faster with the pre-digestion of the nutrients in the soil. When making soil in big piles above 200 gallons things heat up really fast and will need to be turned every couple days until the heating stops and you are then ready to use the soil.

I hope this short and simple home made soil tutorial can help you make your own soil, because once you do, you’ll never go back to bagged soil ever again.

If you have any questions post them up here!