By Julie Boudreau
Last fall, a little something happened to me that inspired this text. In a garden center, upon seeing bags of potting soil sold for $6.99 each, a woman who was passing right next to me was offended: “Come on! It’s so expensive! I can get potting soil for $1.99 at “that big surface store that sells lots of products imported from China”! ” It’s true. She’s right. But…
Never, ever would I encourage a gardener who wants to be even remotely successful in their gardening project to get “cheap potting soil”. And there are many reasons why there is such a big difference in price.
#1 The Bag Is SMALLER!
I mean, really smaller! This famous, very economical bag is sold in a 10 liter format. A beautiful bag of quality potting soil is a 30-liter format. It’s three times bigger!
#2 The Secret Is in the Ingredients
The best cakes and muffins are made with the best ingredients (the same could be said for spaghetti sauce). The best substrates too! I often compare a potting mix to a muffin mix: it’s full of ingredients! There is peat moss which forms the bulk of the contents. There is perlite, a small stone of volcanic origin, very porous. Perlite can trap 4 to 5 times its weight in water. It is also rich in minerals and has the advantage of having an approximately neutral pH. Potting soil also contains vermiculite, another mineral that keeps water trapped in its folds. Sometimes there are even slow-release fertilizers in the mix. And depending on the specialization of the mixtures, the potting soil will contain lime, bark, coconut fiber or sand. The whole thing forms a clever recipe with a well-calibrated dosage. The mixture should be light and airy. It must be both draining and able to retain water!
In less good quality soils, they’re selling illusion! Sometimes, the perlite is completely replaced by Styrofoam balls. Even though these little white balls have the appearance of perlite, they serve no purpose. In fact, their only use is to take up volume, because they are less expensive than peat or perlite. It helps to lower prices!
#3 A Potting Soil That Can Do Everything… That Doesn’t Exist!
It’s amazing! There is a direct correlation between the price of potting soil and what it can do! The cheaper it is, the more it does EVERYTHING! Everything, everything, everything!
Which is extremely unlikely. There are as many potting soil recipes as there are plants! For example, cactus potting mixes contain more sand and are very draining. Potting soils for tropical plants retain water better. And for flower boxes, we look for a potting soil with a high water-retention capacity. If someone offers you the miracle recipe… be wary!
And finally, dare I say it, too often, lower quality potting soils come with their share of small harmful insect eggs and a nice handful of weed seeds! To offer such ridiculous prices, you have to cut corners.
This is why spending two big dollars more on good potting soil is a wise decision.