
I’ve lengthy been within the concept of constructing my very own potting soil. I’ve an ample supply of soil in my again yard and it looks like there needs to be some technique to make it usable as potting soil indoors and out. This might enable me to chop again on the variety of plastic soil luggage I’ve to throw away yearly, get rid of the usage of peat (which is basically problematic for the setting as I’ll clarify later) in addition to save me some cash. So I made a decision to attempt making potting soil from backyard soil.
What’s potting soil?
Most potting soils don’t include any pure soil. They’re usually a mix of peat moss (or coconut coir), perlite or vermiculite, sand, limestone, and fertilizers. They’re usually gentle and drain properly, and are sterile in order that they don’t harbor any ailments. A very good potting soil may have all the required vitamins and properties for potted crops.
The Issues with Potting Soil
One of many greatest environmental points with potting soil is the peat moss. I’ll most likely do a deeper dive into the issues of peat moss sooner or later, however principally you simply want to know that it comes from peat bogs, and the method of harvesting the peat releases loads of CO2 into the ambiance. The U.Ok. is banning the business sale of peat in 2024, and there’s a motion to cease the follow worldwide.
Many of the options to peat have their very own points and something that needs to be shipped from a whole bunch or 1000’s of miles away is all the time problematic. And most DIY potting soil recipes you will discover on-line are actually simply mixing collectively the varied substances present in a typical store-bought bag of potting soil. So that you’ll have the identical points with utilizing plenty of plastic luggage and incorporating dangerous peat or different amendments shipped lengthy distances.
Will this even work?
Earlier than I even start this course of, I do know that if there’s a gardener studying this, they’re most likely already yelling, “No No NO! You’ll be able to’t use backyard soil as potting soil!”
I do understand that backyard soil isn’t superb to be used as potting soil and possibly received’t develop crops as vigorously nearly as good potting soil will. However I’ve been bettering my soil for years by way of composting and different pure strategies, so even when it’s not the best potting medium, I need to see if I could make it workable in any respect after sterilizing it and mixing in a little bit of vermiculite to maintain it from being too heavy.
Backyard Soil to Potting Soil – My First Experiment
The very first thing I knew that I wanted to do was sterilize the soil to make sure that there aren’t any insect eggs, fungi or different potential ailments in it. There are a number of strategies you need to use to sterilize soil, together with heating within the oven or utilizing hydrogen peroxide. I made a decision to make use of the boiling water methodology, as that appeared the best. Spoiler alert: I most likely wouldn’t use this methodology once more in future. I’ll clarify why on the finish.
Step 1: I dug out some good backyard soil, picked out any twigs, rocks or massive worms and left it sitting in a big sieve for a few day in order that any remaining critters might hopefully vamoose.

Step 2: I put the soil in an outdated massive steel pot that we don’t use for cooking anymore after which poured sufficient boiling scorching water over it to make a kind of “filth soup.” (I don’t suggest placing boiling water right into a plastic bucket, it would soften. Glass might crack except it’s actually heavy responsibility Pyrex or tempered glass.) I stirred it up a bit to ensure all soil was totally soaked and submerged within the water. Left it to chill.

Step 3: As soon as it had cooled, I wanted to pressure off the water. I occurred to have a compost sieve (above) so I set this on prime of a plastic bucket to catch the water. I then took an outdated piece of material to line the sieve to create a strainer.

Step 4: I dumped the moist soil into the strainer and left it to empty. It was tremendous sluggish, so I left it in my storage in a single day so no animals would get into it. It took about 24 hours to fully drain out. (I occurred to have some outdated flannel sheets, however I want that I had used a thinner material to pressure this, cheesecloth most likely would have been superb.)

Step 5: I dumped the strained soiled water again into my backyard and I dumped the soil into a pair planting trays to complete. It was nonetheless fairly moist at this level, so I put them on a shelf within the storage to dry out fully. It took for much longer than I anticipated. This was most likely as a result of the truth that it was late October and never very heat out (our storage is indifferent and unheated), plus the truth that I’ve heavy clay soil which actually holds on to the water.
Step 6: After a few week, it was lastly dry. I did my finest to crumble up the massive clumps to make the soil extra manageable. Fairly frankly, it was troublesome. I nearly wanted a hammer or one thing to essentially break it aside totally. Once more, that is seemingly because of the excessive clay content material in my soil. Then I added some vermiculite to make the whole combination a bit lighter and hopefully enable for air move. Right here’s what the ultimate product appears like:

Takeaways:
I’ll be sincere, I’m not thrilled with the consequence. The colour of the soil doesn’t look good anymore. You’ll be able to see within the first photograph the place I used to be pouring within the boiling water, the soil was good and darkish and wealthy. I understand now that utilizing boiling water most likely leaches out loads of the vitamins. Plus which, with my clay soil it appeared to create a serious clumping impact and the soil clumps are a lot more durable than earlier than the sterilization. I’m nonetheless going to attempt rising with it and see what occurs. I’ll submit again right here with my outcomes.
Within the meantime, I’m not giving up on the thought of utilizing backyard soil to make potting soil, however the subsequent methodology I’m going to make use of for sterilization will probably be making a small out of doors photo voltaic cooker to warmth the soil that approach. I feel that may enable me to retain extra of the vitamins and hold the pure soil texture. I feel it would even be significantly simpler than the method above. However I should anticipate a lot hotter climate to proceed with that.
Anybody on the market tried to make use of backyard soil as potting soil? Any victories or ideas? Please let me know!