For Peat's Sake: Conventional Potting Soil And The Environment
It’s a scene every gardener is familiar with: the soil aisle at the hardware store, the various bags of potting soil each promising “Bigger, brighter blooms!” and “Higher veggie yields!”
First of all, the ingredients included in many of these premade potting soils are harmful to the environment. For example, most potting soils include peat moss, an endangered plant. Peat moss is revered for its ability to hold water. However, peat moss grows only in remote areas in Canada known as peat bogs. These bogs can take thousands of years to form, and exist in a state of perfect equilibrium.
A peat bog in Canada - Source
Disturbing these environments can cause imbalances that can have devastating results. Although many companies claim that peat moss harvested from peat bogs will regrow within 25 years, this is most often not the case, as workers and machines harvesting the moss disturb the soil and throw off this ecosystem's delicate balance.
Instead of peat moss, many gardeners recommend coconut coir, a byproduct of the coconut industry that holds water well, is a renewable resource, and biodegrades readily. You can pick some up at your local home improvement or gardening store. Although most chain stores do stock coconut coir, call ahead to make sure they have it.
Perlite and Vermiculite are also commonly found in conventional potting soil. These materials are known for their ability to shed water, making the soil less dense. However, both materials require energy-intensive mining, and I have found sharp sand works just as well.
Perlite mining in New Mexico- Source
Because most premixed potting soils contain ingredients that are pretty different from natural, healthy soil, they often have a chemical cocktail of different nutrients added in, trying to produce a product that is “one-size-fits-all” for a variety of different plants, from beets to begonias to boxwoods. But the truth is that plants have very different nutritional needs, and needlessly adding artificial nutrients to the soil isn’t a guarantee that your plants will be healthy. Also, because the nutrients have been artificially added, they are more likely to simply wash away in heavy rain, leaving your plants unhealthy and polluting your groundwater.
Also, many of the companies that sell premixed potting soils are also heavily involved in environmental industries, including the sale of GMOs and harmful pesticides and herbicides.
However, there are several alternatives to buying conventional bagged soil. First, you can always purchase organic bagged soil, although this is often costly. I find that I can make my own fairly easily, and at a much lower cost.
An Eco-Friendly Soil Recipe- Best for a vegetable garden, but would likely work for flowers, with some tweaking (Adapted from The Ultimate Urban Farming Handbook)
10 gallons coconut coir (available in brick form at most hardware stores, but call and ask first)
5 gallons sharp sand
10 gallons compost (free of weed seeds and pesticides)
5 gallons fully composted animal manure (available in bags at most hardware stores)
This mix, combined with proper crop rotation techniques and occasional nutritional touch-ups (application of compost, compost tea, etc.), is your best bet for an environmentally-conscious garden. Good luck!