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Finding the Right Growing Medium to Propagate Plant Cuttings


Young plant production continues to be a growing segment of the horticulture industry. Over the last several years, many producers have moved from seed germination to cutting propagation. This has become popular for specialty varieties and branded plants. While young plants are still produced with seed germination and plugs systems, the propagated and rooted cutting market has evolved into new processes with specialized equipment. Several companies have developed machinery to wrap paper and other materials around growing medium to form small pots.

Characteristics of Paper-Wrapped Pots for Propagating Cuttings 

These miniature pots are available in assorted diameters, ranging from 15 mm up to 120 mm (5/8” – 4.75”). They represent an interesting practice for organic cultivation as some of these paper-wrapped pots are 100% bio-degradable. They are made by extruding growing medium into ‘tube-shaped’ outer wrapper and gluing the seam inside the wrapped tube. When the medium “tube” is filled, the paper-wrapped tube is cut into a specific length to form paper pots that are placed into individual cells within a growing tray.

The smaller size paper-wrapped pots (15-35 mm) are used mostly for cutting propagation. Larger sizes are used for propagation of greenhouse foliage, woody ornamentals for nursery and ready-plant annuals for the landscape trade. There are different needs for growing medium for each of these applications.

Rosemary cuttings rotted in 25mm  paper-wrapped cells

Rosemary cuttings rooted in 25mm paper-wrapped cells. Source: Premier Tech

A Machinery That Requires a Growing Medium Free of Sticks

With these types of pots, the growing medium must be free of sticks to avoid tearing the wrapping or damaging the saw blades that cut each pot. Clean product works better with automated machinery and there are fewer worries of bridging small cells with plug trays. Most growers prefer a fibrous growing medium that has good air porosity. It is a challenge for peat moss producers to remove all sticks and small tree roots from Sphagnum peat moss, because they are found naturally, and the challenge is to screen out this debris while retaining the fiber of the peat moss to have a well-structured growing medium.

The industrial division of Premier Tech, Premier Tech Systems and Automation, has developed an improved screening system to process Canadian Sphagnum peat moss with minimal fine peat-moss particles, that is virtually stick free. This innovative equipment and process of screening Sphagnum peat moss, along with a precise blend of coir (horticultural grade), perlite, vermiculite, limestone, wetting agent, low soluble starter nutrient and active ingredients, are used in formulating PRO-MIX germination and young plant production growing media: PRO-MIX®  FPX, PRO-MIX® PGX and PRO-MIX® YP.

PRO-MIX® Growing Media Perfectly Suited for Cuttings

These 3 growing media work very well with cuttings including those in paper-wrapped pots. To determine which one works best with your cultures, here is what differentiates them:

 PRO-MIX Active ingredient growing media

PRO-MIX® Growing Media Perfectly Suited for Cuttings

These 3 growing media work very well with cuttings including those in paper-wrapped pots. To determine which one works best with your cultures, here is what differentiates them:



  • 80-90% Fine Canadian Sphagnum Peat Moss – Short fiber
  • Perlite – Plug Grade


  • 75-85% Fine Canadian Sphagnum Peat Moss – Short fiber
  • Vermiculite – Plug Grade


  • 45-55% Canadian Sphagnum Peat Moss – Short Fiber
  • Coir (horticultural grade) 
  • Perlite (horticultural grade)

Minor Components for the 3 products

Calcitic and dolomitic limestone (pH adjuster), wetting agent and a starter fertilizer charge.

Active Ingredient

They are all available with BIOFUNGICDETM, to accelerate seedling development and plant establishment, reduce the need for fungicide drenches and strengthen plant disease resistance. * BIOFUNGICIDETM is only available in the US.

Plug trays with PRO-MIX YP

Plug trays with PRO-MIX YP. Source: Premier Tech

Products Properties Comparison

Differences Contains fine perlite Contains fine vermiculite Contains coarse perlite and coir fiber
Water Retention Medium High High Medium High
Drying Rate Moderate Slow Medium
Leaching Ability High Medium Medium
Recommended Application

Ornamental seedlings and plugs

‘water-sensitive’ seed varieties

Vegetable seedlings and plugs

Seed varieties that prefer higher moisture

Rooting of cuttings

Germination of large seeds

Ideal for

Growers that are heavy waterers

Growers that are light waterers

Growers that are heavy waterers

Humid conditions

Less frequent watering

Rooting cuttings

Recurring root diseases

Earlier root ball harvest

Fast root establishment

In summary, finding the growing medium best suited for the propagation of your cuttings is up to you! By knowing the needs of your crop, you will find the one that meets your criteria.

PRO-MIX® BIOFUNGICIDE™ growing media products are only available in the US. In Canada, the PRO-MIX BIOSTIMULANT is available which can help root hair development on the roots and provide improved plant nutrient absorption. Check for the availability of products with your PRO-MIX sales representative. 

For more information, contact your Premier Tech Grower Services Representative.


BLOE          PEEJ              LAWL

Ed Bloodnick
Horticulture Director
US-South East

JoAnn Peery
Horticulture Specialist
US-Central, Canada-Central

Lance Lawnson
Horticulture Specialist
US-West, Canada-West


Troy Buechel
Horticulture Specialist
US-North East

Susan Parent
Horticulture Specialist
Canada-East, US-New England

Jose Chen Lopez
Horticulture Specialist
Mexico, Latin & South America


PRO-MIX® is a registered trademark of PREMIER HORTICULTURE Ltd.

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