Potting Mix: Is It Helping or Hindering Your Garden

Last month, one of our customers came into the store looking for help problem solving why her plants might be dying. She brought in a sample for us to look at which was potted simply with a mulch purchased from her local hardware store.

Generic potting mixes are full of nitrogen, phosphorus and potassium; all the nutrients essential to plant survival. Although plant life cannot survive without these nutrients, soil mixes fail to provide adequate aeration to plant roots, and when used alone, they significantly increase the chances of inborn pests like fungus gnats.

The solution to this problem and the recommendation we gave to the customer was to transition her plants from a generic store-bought potting mix to a homemade mix composed of coco peat, perlite and expanded clay. We like to recommend this in ratios of six parts expanded clay to four parts coco peat and four parts perlite.

Expanded clay, otherwise known as clay balls or LECA (lightweight expanded clay aggregate) is an essential component of any well-rounded potting mix for several reasons. Firstly, expanded clay makes it easier to water your plants. Unlike plants that are potted in soil, using LECA raises the plant, so it’s not sitting in water permanently. Plants are therefore allowed to drink when they’re thirsty, from the water soaked up by the aggregate, which reduces the risk of issues like overwatering and root rot.

Secondly, unlike soil, expanded clay is not a live growing medium. Essentially, what this means is that expanded clay cannot provide nutrients to your plants. It also means that expanded clay cannot provide nutrients to insects, which reduces the chances that the chances of common inborn pests like fungus gnats.

When considering the transition from soil to a more thoughtful handcrafted mix, it is essential to make sure your plants are still getting all the nutrients they need to thrive. At Aquaponics WA, we supplement the water our plants receive with a one-part nutrient. We use Ag-Grow Grow or Ag-Grow Bloom to ensure our plants stay healthy and thriving