As Seen in Greenhouse Grower Magazine

Retailing Potting Mixes

Lane Greer and James L. Gibson
NCSU Floriculture Research

Grandma deserves a gold medal! Not just for putting up with our childhood shenanigans, but also for growing prize-winning geraniums in heavy, non-porous, topsoil-rich potting mixes that used to be the only option. Today, in a world where people spend fewer hours at home than ever before, we need products that require less maintenance and give immediate performance, from washing machines to potting mixes. Our industry, through research and attention to grower needs, has discovered that soil used in containers doesnít perform as well as soilless mixes. Nowadays, soil (dirt) stays in the garden, while soilless mixes rule containers.

Due to the recent popularity of container gardening, more consumers have become familiar with soilless mixes. Drought and water restrictions around the country have been a contributing factor to the integration of container gardens into the rest of the gardening world. Consumers are beginning to understand the nature of soil-water relationships in container gardens. However, this understanding expresses itself more in terms of time spent watering, rather than a familiarity with components of potting mixes. In other words, just because a customer recognizes that her pots are lighter does not mean that she knows peat is being used instead of topsoil. More customers will begin to question which components are favorable to their watering practices, and you should be prepared for this. As producers, it is easy to forget that we donít see the mature plant and its fully developed root system. Customersí needs are addressed by educators like Jim Wilson, who should be complemented for their contributions to customerís understanding of the essentials of potting mixes. These individuals serve as the bridge between growers and consumers and open the door to marketing potting mixes.

Retail Potting Mix Photos


Making potting mixes fun, interesting, and exciting to customers is the name of the game. Soil and soilless mixes are something that most customers don't really pay attention to, so you must emphasize what the product does rather than what the product is. In other words, as in all marketing, nobody really wants to buy the product; she wants to buy what it can do for her.

In order to focus on what the product can do for the customer, grower-retailers must be prepared to answer the following questions about mix components.

  • What about compost? Compost quality varies depending on source, length of composting period, temperature and moisture during that period, and even where the composting occurred. For instance, Dr. Harry Hoitink at The Ohio State University has conducted extensive research on the disease suppression of composts and found that compost piles located in the open are more suppressive to diseases than those located under a roof. Because composting is a complex issue, it is even more imperative that we make this easy for customers to understand. In general, compost holds more water than peat, contains some nutrients, and has some disease suppression. However, mixes that contain only compost are not used because they tend to hold too much water and have a high soluble salt content. Compost, rather than garden soil, should be used for container gardens because diseases are often present in garden soil. Soil that has been pasteurized may be appropriate for containers; the advantages of soil include its buffering capacity and its contribution to bulk density.
  • What mix is best for containers? The best container mix will depend on several factors: how often and well the customer is watering, whether the container is in sun or shade, the type and age of plants in the container, the season, and the container itself. Often, the major concern of customers is to spend less time watering. As mentioned above, compost mixes generally hold more water than peat mixes. Coir also holds more water and is easier to re-wet than peat. If the container is a hanging basket, weight of the mix when wet is an additional concern. Larger aggregate materials such as perlite and bark assist in drainage.
  • What is coir? Many consumers have heard of coir but are uncertain as to what it really is. Perhaps the two great advantages of coir are that it is considered sustainable (there is always some question with peat harvesting), and it holds more water, which makes it an excellent choice for containers. The disadvantages may include the need to use more nitrogen fertilizer and the possibility of salt damage. The latter can vary greatly according to the origin of the coir.
  • How can I use "green" ingredients in my potting mix? People are beginning to hear the message that they should be more sustainable. This is interpreted differently by everyone: some recycle more often, some set their thermostats lower or drive more fuel-efficient cars. Still others attempt to incorporate sustainability into their gardening practices and ask about things such as recycled newspaper, yard wastes, or using alfalfa meal as a fertilizer. Itís a good idea to have mixes on hand that include these kinds of ingredients.
  • Specialized mixes for special gardens, e.g., heavy clay soils for water gardens and lightweight mixes for rooftop gardens. Be sure to have special blends displayed in the appropriate places in the retail area.

There is a small percentage of consumers who care about things associated with mixes, such as what wetting agents were used, water holding capacity, and media pH. By and large, however, this is overkill for customers. Look at the success of the floral preservative industry. The small sachets that accompany bouquets donít concentrate on the ingredients in the package; they simply provide instructions on how to use the preservative to enjoy longer-lasting flowers.

To make these esoteric issues easier to understand, the Mulch and Soil Council (MSC), formerly known as the National Bark and Soil Producers Association, is in the process of establishing a Product Certification Program 1, 2 that will provide consumers with designations for certified products. The MSC is a group of companies that manufacture and sell consumer and grower media, soil amendments, and mulches. Currently, the four categories include premium potting soils, standard potting soils, landscape soils and soil amendments, and mulches. For more information on this development, visit the MSC website at

Workshops and Seminars

Incorporate information on potting mixes into workshops that focus on other topics, such as annuals, water gardening, and container gardening. For instance, lots of homeowners try to recycle their containerized soils year after year. We need to educate consumers on the feasibility of this practice. Does this promote disease? Does this promote good or poor growth? How does this affect aeration, nutrient reserve, water holding capacity? There are two approaches to take. We can either educate consumers about reconditioning these mixes, or we can advise them to add old container mix to their garden soils and add fresh mix to their containers. It is a win-win situation either way, because we are still retailing potting mixes. Re-potting demonstrations can include information on a one-year program that involves ripping and replacing plants four times a year. Table 1 provides a timetable with strategies for year-round container gardening.

Table 1. Suggested action steps to sell potting mix and plants.



March-April (first season)

Fill container with fresh mix and plant an early spring garden with plants such as osteospermum, snapdragons, and alyssum.


Plant summer annuals (e.g., marigolds, petunias, cosmos, and zinnia) and top-dress with a slow-release fertilizer


Remove summer annuals, including root system. Churn the mix. Have the mix tested for pH and EC. Plant the fall garden (mums, pansies, mustards, and spring bulbs).


Plant winter annuals (kales, parsley, and Fall MagicÔ perennials).

March-April (second season)

After spring bulbs flower, recondition the mix for container use for a second year, or incorporate the mix into garden soil.

Other issues that should be addressed at potting seminars include drainage, container size, and use of saucers. A common question posed by consumers is, "Should I put a layer of gravel in the bottom of my containers?" The definitive answer is no, as this contributes to poor drainage because of a perched water table. A perched water table effectively means there is less air in the mix, and this may promote disease or introduce nutritional disorders. Poor drainage also results when "trash" is placed in the bottom of containers. Large, deep containers need to be watered less often and provide a better growing environment for plants. Success with these containers has contributed to the popularity of container gardening.

As grower-retailers, we often see a 20" container much as we see a 6" azalea pot. We donít experience the dry-down that consumers experience in the dog days of summer. Before ringing up the sale, stress the importance of using a saucer to provide a reservoir to keep plants from wilting when customers forget to water. Have an inventory of saucers from which to choose.

Donít forget to tie in fertilizer sales with potting mixes. Slow-release fertilizers are most often used with container gardens. These are preferred by customers, who usually top-dress their plantings once or twice a year.

Retail Potting Mix References


Displays should emphasize use of the mix: What is the mix used for/good for? Displays could also show effects of aging on mixes. Consider having a "bin-type" layout for all potting mixes sold. This gives the consumer an idea of what is in the bag before they purchase it. Also display the effects of aging that a mix will undergo, as this shows the importance of reconditioning the mix in container gardens.

Another retail item that could be marketed as a garden amendment is your recycled production mix. For most grower-retailers, this "dump pile" includes diseased plants, plastic, and pesticide residues (particularly PGRs). If time and space are available, start a pile now that is free of these contaminants. Early spring customers often need topsoil and mulch. Donít miss out on these sales. Good signage should lead customers to products (bulk topsoil, hardwood mulch, pine bark) and services (repotting services, soil testing, seminars on year-round container gardening).

Most retailers market their mixes in a separate area, away from customer traffic, that is not user-friendly. The loading zone is a common site on the grower-retailer property. Consider incorporating mix displays into the plant sales area. Have the plants, the mix, and the final product (the combination of the two) displayed in a highly visible area. Highlight your retail mixes by growing plants in those mixes, rather than using your commercial mix. This strategy will also improve your experience with these materials.


Container gardens have high profit margins. As conscientious grower-retailers, we need to consider the needs of the customer when planting. We are selling both a product and a service, so we want all the right ingredients in our containers. Not only should we produce high-quality, disease-free plants, we should also keep in mind that the right potting mix is key to continued growth and health of the plants. By considering the needs of the customer, we can decrease the amount of time they will spend maintaining their container gardens. These practices will ensure satisfied customers and repeat business.


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