Perfect Potting Soil

Most topsoils, triple mixes, or garden soils don’t stand up to the strict standards that most home owners have when it comes to potting soil. Potted plants require finely tuned soil conditions in order to flourish.

Acidity, measured on the pH scale is an important factor. Most plants require a neutral soil acidity. Potting soils that can be used for general plant applications should be tested regularly for pH. There are some indoor plants that require slightly acidic or slightly basic soils, and this must be taken into consideration when planting.


Another crucial factor to be mindful of when selecting a potting soil is the fertilizer values. Fertilizer nutrients such as nitrogen, phosphorous, and potassium are necessary for plant growth. Having proper amounts of these nutrients, and in the right ratio can be make-or-break for potted plants. Consistent testing for these nutrients is essential for potting soils.

Aside from the main fertilizer nutrients, trace elements are also critical to the success of potted plants. Monitoring how much calcium, magnesium, sulfur, sodium, boron, iron, manganese, copper, and zinc is in a soil contributes to maintaining a healthy soil.

Potting soils must also be tested for water retention and particle composition. Potted plants have specific moisture levels and air flow requirements that they need to grow. Having the perfect mixture of sand, silt, and clay in a soil is necessary. Most gardeners and soil scientists refer to this soil “sweet spot” as Loam.

As you can see, there are TONS of specific values that must be tediously tested for when building a proper potting soil. Many home owners also lean towards sterile soils when growing potted plants. The advantage to sterile soils is that they are completely weed and pest free, however sterile also means that these soils are totally dead. There is no micro organic activity, which is essential to healthy plant growth. Microorganisms in the soil process nutrients, and they also produce polysaccharides that hold soil particles together. This binding contributes to that perfect water retention and air flow.


BigYellowBag’s Black Garden Soil is held to very specific standards. With professional agronomists visiting our local distribution centres frequently, the acidity, fertilizer values, trace elements, and composition of our soil are always dialed-in to perfection.

Cameron Shimoda

Garden and Soil Enthusiast