Soil-less Potting Mix 101

While all plants share common needs regarding their potting medium, such as proper air circulation and drainage, there are numerous options in terms of mix composition. Whether you choose Molly’s Potting Mixes or create your own recipes at home, consider the following guidelines:

• The mix should have a good balance of large, medium, and smaller particles to ensure proper air circulation and drainage after watering.
• Hard materials will decompose at a slower rate than soft ones, reducing compaction which could restrict root growth and health.
• A mix of organic and inorganic (mineral) materials will help mimic the plant’s natural growing environment.
• Popular ingredients include tree bark, sphagnum (less sustainable) or coco (more sustainable) peat, perlite, sand, vermiculite, rocks, and other organic and inorganic ingredients.
• Soil-free ingredients reduce the likelihood of disease, pests, and soil-borne pathogens.
• Make sure to test for pH levels and target a value around 6.0 to maximize the plant’s ability to absorb nutrients
• Check with the manufacturer/store you buy your potting mix from to find out how often you should re-pot your plants using fresh mix.

💚 Pro-tip: Many people confuse potting mixes with fertilizers. Potting mixes are simply a reference to the medium in which plants are growing (e.g. soil, soilless, hydroponic) while fertilizers contain a mix of macro (e.g. nitrogen, phosphorous, potassium) and micro (e.g. copper, iron, manganese) nutrients that plants need. Potting mixes, excluding any organic ingredients they may contain, usually have minimal nutrients so adding a fertilizer is a necessary step to ensure plant health.