Sun Gro’er Blog

Review of Major Growing Media Components

Review of Major Growing Media Components Featured Image

By Dan Jacques and Ron Walden, Sun Gro Horticulture –

The major role of a growing mix is to support the plant, while holding water and nutrients for the plant to use during growth. There are five main components commonly used in making growing media: peat moss, bark, coir, perlite and vermiculite. This article describes the components and outlines desired properties of mixes for various uses in greenhouse production.

Read: Review of Major Growing Media Components

Trends in Media Mixes

A Q&A on trends in media mixes, with Sun Gro’s Dan Jacques, Technical Services, and Kathryn Louis, Research & Regulatory Services – 


  1. What can you tell me about Sun Gro’s media mixes and components products for greenhouse growers?

Sun Gro is the largest supplier of professional growing media in North America.  We also are the leading manufacturer of Canadian Sphagnum peat in North America.  We combine the best quality components such as bark, perlite and vermiculite, with our peat, to make up growing media for professional and consumer uses. Sun Gro has a dedicated research group working on new and innovative products such as the silicon enriched RESiLIENCE™ products.
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  1. What trends or new developments have you noticed regarding media mixes/components or equipment/technology?

Increased interest in Natural & Organic media, as well as custom blend option of incorporation of biological organisms that enhance growth or disease resistance has been the biggest changes we have seen in the industry.  It seems to be going from a niche market to becoming more main-stream.

  1. Do you have any new products or anything that’s currently in the works for this category?

Sun Gro has a number of OMRI listed Natural & Organic growing media for both professional growers and consumers.  In addition to that, we offer Natural & Organic growing mixes that include mycorrhizae, which have been shown to enhance phosphorus uptake.  We also offer custom blended Natural & Organic mixes which include the bio-pesticides RootShield™ and RootShield Plus
Our newest product line, both in our standard formulations as well as in our Natural & Organic products, is the introduction of our RESiLIENCE™ also known as RSi mixes.  This is a patented process of incorporating plant-available silicon into growing media.  The addition of RESiLIENCE™ is now standard in all professional and consumer mixes.
There has been a great deal of  research in recent years on the benefits of incorporating silicon into growing mixes, both at Sun Gro and in the Academic and Government research areas.  Some of the key results indicate potential for improved root development, better branching, drought tolerance, thicker stems, earlier flowering and stress avoidance.  University research has also shown improved tolerance to some diseases and insects.

  1. How do you see media mixes and equipment changing in the next few years?

The industry overall seems to be shifting to larger growing operations, which tends to gravitate toward more automation.  In turn, packaging product in formats that better lend themselves to automation seems to be a big trend.  Many are going away from smaller formats, such as 2.8 cubic foot loosefill and 3.8 cubic foot compressed products to bulk/mini bulk products and larger compressed formats such as 110, 120 or 135 cubic foot compressed bales.

  1. What products are most popular with your greenhouse clients?

Mixes such as Fafard 1P RSi, Sunshine #1 RSi, Sunshine and Fafard #15 RSi, Metro Mix 820 RSi, Metro Mix 830 RSi, Metro Mix 852 RSi, Fafard 3B RSi and Fafard 52 RSi are some of our top selling mixes.

  1. Have you noticed growers looking for sustainable solutions? What are they asking for?

The trend has been to move away from the “sustainable” label to looking more at whether or not components are environmentally conscious.  Media containing components such as Canadian Sphagnum Peat, composted bark, coconut coir and locally available composts would fall into these categories.  The larger format packaging also reduces waste.  Another area where we have seen significant increase, has been in Natural & Organic mixes.

"Dirt and Fert" for Basket Production

Potted plants in Greenhouse
Plants placed above may not receive as much attention as those below. Using CRFs may help avoid nutritional issues.

Interesting how some things don‘t change; hanging baskets are still big business! When you think about it, hanging basket culture is in a league of its own and deserves special
attention. The entire objective of growing a hanging basket crop is different than that of a pack or small pot. The objective is usually to grow big, full, overflowing plants that typically remain in the container. While the objectives for packs and small pots is to grow colorful, compact plants that are proportioned to the pot. When it comes to soilless media for hanging baskets, the initial challenges are to avoid keeping it too wet, depending on the production program employed. Thereafter, when plants are full and sized up, the major challenges are always moisture supply and weight.
–Rick Vetanovetz, Dan Jacques, Mark Thomas and Ron Walden
Read More in The Sun Gro’er Issue 7/1 (2012)
Leer más en The Sun Gro’er Issue 7/1 (2012) Spanish/Español

Update on Sun Gro Growing Media

Sun Gro Horticulture is the largest provider of professional greenhouse mixes in North America. We offer a wide range of mixes covering all the needs of the greenhouse industry, from seed/cutting propagation to general production. All of our standard mixes contain a liming agent to adjust medium pH, a lean nutrient starter charge and a proprietary wetting agent, which helps avoid major wet-out issues. In addition to our standard media offerings, Sun Gro has a few new formulations for your consideration.
–Dan Jacques, Ron Walden
Read More in The Sun Gro’er Issue 5/2 (2010)
Leer más en The Sun Gro’er Issue 5/2 (2010) Spanish/Español

Media, Tissue and Water Testing for Good Growing

Planting flowersRead More in The Sun Gro’er Issue 1/2 (2003)
When do most growers test media, tissue or water in the greenhouse? If your answer is “only when there is a problem”, you are probably right. However, that is not the only time that growers should be testing. Growers should be testing at least for media pH and EC on a weekly or bi-monthly basis (on-site testing) and should also be conducting complete tests 2 or more times per crop for major crops (complete lab analysis).
Tests should not be limited to media pH and EC, but also to water alkalinity, EC and pH. This is especially important if growers are having problems maintaining pH in their mixes. Knowing the alkalinity of the water and fertilizing according to the alkalinity goes a long way in helping assure a successful, high quality crop. This is a separate topic in and of itself.
Continue reading “Media, Tissue and Water Testing for Good Growing”

Sun Gro's Technical Specialists

Read More in The Sun Gro’er Issue 1/1 (2003)
Sun Gro has seven main Technical Specialists, three in the West and two each in the Central and East regions. Their duties include Quality Control (QC) work with specific plants, along with providing technical support for specific sections of their region. Technical support includes work with complaint handling, training and custom blends. These are also the Sun Gro staffers who will be providing most of the content for the Sun Gro’er Newsletter. Here is some basic information that will allow readers to get to know them a little better: Continue reading “Sun Gro's Technical Specialists”