In the Fall of 2012, we introduced PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ for organic growers. This was Premier Tech Horticulture’s first professional organic growing medium listed with OMRI for commercial production of organic grown vegetables, herbs and edible flowers. Market reception was relatively good, however, we received some valuable feedback from our customers about product performance and some needed improvements. These included initial and long term wettability/drainage and a small modification of the pre-plant fertilizer charge.

To address these points, we made improvements to PRO-MIX® MP MYCORRHIZAE™ ORGANIK™. The first challenge was finding an organic wetting agent that works as well as a synthetic (chemical) wetting agent. We evaluated over 25 products in horticulture, agriculture and other industries inside North America and abroad. We found that the organic wetting agent we currently use is the best available; however, it does not work as well as a synthetic wetting agent.

To address the hydrophobic nature of peat, we increased the moisture content of the product slightly and replaced some of the peat moss with horticultural grade coir at a rate of approximately 27%. The addition of horticultural grade coir improves the wetting/rewetting ability and water characteristics considerably.

This modification improved the wetting ability of this product by 50% over the previous PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formulation. In addition, the combination of Sphagnum peat moss, horticultural grade coir and perlite provides better air porosity and drainage than the previous PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formulation.

We also worked to improve the pre-plant organic fertilizer charge in the product. The challenge was finding an organic fertilizer that is accepted by US and Canadian regulations as well as organic certifying bodies. We made the change from a soy-based fertilizer to a poultry-based organic fertilizer that contains humates and seaweed granules. This fertilizer is accepted by OMRI and Quebec Vrai for both US/Canadian markets. This fertilizer also provides a more uniform and consistent pre-plant organic fertilizer charge than found in the previous US formulation.

With any product change, we evaluate the growth performance with greenhouse plant growth trials. For this we use a traditional growing medium and synthetic fertilizer for establishing the base comparison.

Following are pictures of plant growth trials comparing standard PRO-MIX® LP-15 with water soluble fertilizer (traditional plant production) versus the previous version of PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formulation and new, improved PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formula. Both organic growing media were fertilized with Daniels 10-4-3 Organic fertilizer in this plant growth comparison.

Cucumbers at 33 days after sowing PRO-MIX MP MYCORRHIZAE ORGANIK
Cucumbers at 33 days after sowing
Tomatoes at 16 days after transplanting PRO-MIX MYCORRHIZAE ORGANIK
Tomatoes at 16 days after transplanting


Basil at 35 days after transplanting PRO-MIX MYCORRHIZAE ORGANIK
Basil at 35 days after transplanting


Dianthus at 69 days after transplanting PRO-MIX MYCORRHIZAE ORGANIK
Dianthus at 69 days after transplanting

Growth trial comparisons demonstrated improved plant growth for those grown in the new PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formulation compared to the previous version of PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ formulation.

Organic standards... How reliable are they?

In order for products to be ‘certified organic’ or listed as components suitable for organic agriculture/horticulture use, independent authorities from non-profit organizations are mandated to review industry produce and products. For growing media, the ingredients and manufacturing methods are reviewed by organizations, such as OMRI and Canadian authorized certifiers to be sure all materials and products are in compliance with organic standards. These certifiers have been operating for over 10 years and have high credibility in industry.

Advantages of using PRO-MIX® MP MYCORRHIZAE™ ORGANIK™for certified organic plants

  • Compost is great in soil, but when added to growing media, it can reduce air space and cause uneven in growth. PRO-MIX® MP ‘compost-free’ and provides consistent growth with the basic fertility derived from the food industry, without manure and risk of pathogens (ie: e-coli).
  • Simplicity and reliability of manufactured organic growing media. Some growers mix their own media, because they may believe that organic products are generally not of good quality. PRO-MIX® MP has the same qualities and standards as other PRO-MIX® products. It is superior in composition and performance compared to grower prepared mixes and other commercial organic mixes.

To summarize, the new PRO-MIX® MP MYCORRHIZAE™ ORGANIK™ product provided:

  • Better wetting /rewetting (improved by 50%)
  • Improved plant growth (from 12-35%, depending on plant variety)
  • Better crop uniformity