I grin when I see stacks and rows of commercial potting soil bags at grocery stores, hardware stores and at greenhouses. The so-called “potting soil” or “black earth” has become an industry built on misconceptions.
The bagged material does not contain soil. Sure it looks black and earthy and the real thing for your plants, but it delivers almost no nutrients. I call it a “lifeless substance”. No wonder the bags are heavy for their size; they are 70 percent moisture! Some folks mix it in with existing garden soil to loosen the soil up a bit. It’s a waste of money!
Women love the packaged bags. They say the black earth feels fresh and soft. It’s so soft it disappears from excessive rainfall and also from too much hot sun.
There are people who applaud local grown food, self-sufficiency, organics, saving the planet and stuff like that and they buy the bagged “black earth”, which contribute to land degradation and pollution as they are mined, processed, packaged and shipped.
Because there are no regulations to govern potting soil, the formula varies by the manufacturers. I looked at the many different brands and found they had roughly the same kind of ingredients. Potting soils are based on a combination of peat moss, perlite and vermiculite. Organic Choice is different. It is the only one I saw that has “pasteurized poultry litter”, which brought a chuckle. Did the hens eat organic grains? The other ingredients: 50 percent composted bark, sphagnum peat moss and organic wetting agent. See what I said about it not being a soil.
I checked the labels on potting soil bags at local outlets to see about nutrients. Most have 30 percent organic matter, maximum moisture of 70 percent, and get this, 0.14 percent nitrogen. One brand of Premium Potting Mix has 15 percent organic matter, moisture of 70 percent and nitrogen is only 0.07 percent. That’s almost nil for nitrogen. Look at the moisture content!
It’s no better when it comes to phosphorous and potash – 0.01 percent phosphorous and 0.03 for potash.
Why not make you own compost? If you have soil and compost, you’ve got the basic ingredients for making your own potting soil. Instead of brown bagging your leaves and grass clippings, compost them and add it to your soil. Rotted sawdust from untreated lumber is another excellent ingredient for a compost pile. Compost is 100 percent organic matter.
Sow buckwheat or red clover in part of your garden and turn it down (with a shovel) before a frost or before it goes to seed. The next season you’ll have no weeds and lots of real organic matter in the soil.
Remember there are major differences between potting soil and your typical garden soil found outdoors. Garden soils are usually loamy, heavy, rich soils. Good garden soil is full of organic matter. The natural cycle of decay and growth keeps soils richer, and the interaction of many plants, insects and especially worms balances the soil.
That hasn’t happened to the stuff in the plastic bags with bits of sticks in it.
