Extension Logo
Extension Logo
University of Minnesota Extension

How to Select the Right Potting Mix

Going to the garden center to purchase potting mix can be a little overwhelming. With many types of products to choose from, it can be difficult to know which one will be best for the plants you intend to grow. There are many types of bagged potting mixes and garden soils available. Some are intended to be used in the ground to supplement or fill areas for gardens. Other products are intended for plants growing in containers and pots. The latter retain moisture, provide air space for roots, and are free from weed seeds, insects and diseases. Potting mixes, also called soilless mixes or soilless media, usually contain combinations of peat moss, pine bark, coir, perlite and vermiculite.

Garden soils are not a good choice for containers because the soil can quickly become compacted and waterlogged, reducing air space around the roots. This can lead to poor or stunted growth. Garden soils can also contain weed seeds, insects and diseases if they haven’t been pasteurized.

Specialty potting soils
While the all-purpose, general type potting mixes will work fine for almost all annual flowers and mixed containers, there are some crops for which specialty mixes might perform better. Orchids require excellent drainage and most general potting soils hold too much water and lack enough air space. Components of mixes for orchids may vary, however, coarse materials are often used to allow for plenty of air movement through the medium. Succulents and cacti, require better drainage than annual flowers and in many cases prefer clay pots as well.

Summary: Rules of Thumb for Choosing a Potting Mix for Pots and Containers

  1. Potting mix bags should be light, fluffy and DRY. Avoid bags that are saturated with water or seem to be heavy and compact. This is especially important for potting mixes that contain fertilizer pellets (often labeled as continuous feed, controlled release, timed release or slow release).
  2. Look for a potting mix that contains peat moss, pine bark or coir and perlite or vermiculite.
  3. Fertilizer may be in the mix in the form of a "starter charge" or “continuous feed” formulation.  Adjust your fertilization practices accordingly.
  4. Potting mixes also contain a wetting agent to make the soilless media wet easier. Organic potting mixes may contain yucca extract, a natural wetting agent.
  5. Potting mixes may contain moisture retaining amendments such as gels.

Choosing the correct potting mix for your houseplants and containers will provide the best foundation for your plants, and get them well on their way to living happy and healthy lives.

For more information on all your gardening questions, visit: www.extension.umn.edu

Page survey

© 2023 Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.