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How to make potting soil? Asked by a reader.
I know there are thousand different recipes and articles on how to make potting soil. Some are good, some could use something more.
While experimenting I came up with a potting soil I can use, and I am very happy with. I didn’t use any scientific information I just tested out different mixtures to come to my final conclusion and “perfect” mixture.
My potting soil mix
Let me give you a short explanation of how and what I use for my potting soil.
I tend to use a bucket as measuring cup (if you can call this a cup?)
First, I fill one bucket with peat moss, I fill up the bucket with water and let this soak for at least 20 hours.
Peat moss is very acidic but tends to lose some acidity when soaked in water. Dry peat moss takes a lot of time to soak up water when it’s dry)
I also use one bucket of soil, this can be old potting soil I pile up outside. If I don’t have any leftover potting soil, I use regular soil. This soil is sterilized by means of a microwave oven to make sure no pathogens or viable weed seeds are in the soil. Reusing potting soil is something I have been doing for quite some time and for me, it works out really well.
Next, I fill a bucket with compost.
In our city, we’re lucky we can buy compost in great quantities for a really small price. This compost is made using the hot composting method so pathogens and viable seeds aren’t a problem.
Update: Since then I make my own hot compost. If you want to know what it takes to make compost, click here
I also use half a bucket of sand (sharp river sand) to make sure the potting soil drains well.
Above mentioned are the basic materials I use to make my potting soil.
Now to amend my potting soil, I use a hand of seaweed minerals (contains high amounts of calcium). I also amend with basalt meal (really small quantity, not even half a hand full. Last but not least, I amend with an organic fertilizer 6-3-12 NPK with some added magnesium. Because this fertilizer is slow release, there’s no
danger the plants will get burned.
This whole mixture, I mix up in my wheelbarrow and I get my really good potting mix. If you want now, you can make the same potting mix as I do.
In the meanwhile, I already changed my potting soil mixture. I tend to use a lot of organic matter in the form of compost
and I don’t amend with fertilizer anymore. I make my own liquid fertilizer
and I use mealworm frass as dry fertilizer. Of course, I also use about 10 to 20% of vermicompost to make the soil alive and healthy.
So this is it for this blog post on how to make potting soil. I hope you’ve found it interesting. If so, please share with friends and other gardeners.
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Thanks for reading and see you in the next post.