PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix
PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix
PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix
PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix
PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix
PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth Pro-Mix

PRO-MIX® HP® Biostimulant Open Top Grow Bags - Enhanced Plant Growth

$13.95 CAD

The PRO-MIX HP Open Top Grow Bag is more than just a growing medium; it's a comprehensive solution for enhanced plant health and yield. Whether you're a hobbyist or a professional grower, this grow bag will transform your gardening journey, leading to healthier plants and more successful harvests.

SIZE: 7 Gal/28.3L

7 Gal/28.3L
3.5 Gal/ 14.2L

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Enhance Your Growing Experience with the PRO-MIX® HP Open Top Grow Bag

Welcome to the next level of gardening with the PRO-MIX HP Open Top Grow Bag, your ideal companion for cultivating a wide range of plants. Designed with both the novice and expert gardener in mind, these grow bags come in two convenient sizes, 3.5 gallons (14.2 liters) and 7 gallons (28.3 liters), to suit various planting needs.

Experience the ease of planting and transplanting with our user-friendly design, featuring eight pre-made drip holes for efficient watering and a tear-off opening that simplifies setup. The loose-fill medium accommodates your plants comfortably, ensuring a hassle-free gardening process.

But what truly sets the PRO-MIX HP Open Top Grow Bag apart is its innovative open top design, providing unmatched aeration in the root zone. This thoughtful feature guarantees equal air distribution, a vital aspect for fostering healthy root growth and, in turn, robust plant development.

Taking plant care a step further, these grow bags are enriched with mycorrhizae. This powerful addition not only boosts root growth but also significantly enhances your plants' ability to absorb water and nutrients. More than just a growing medium, the inclusion of mycorrhizae actively increases your plants' resilience against a variety of environmental stresses, including drought, soil compaction, salinity, low fertility, and the challenges of transplanting.

With the PRO-MIX HP Open Top Grow Bag, you are not just purchasing a product; you are investing in a superior growing experience. These bags are crafted to provide the optimal environment for your plants, ensuring they thrive from the root up. Whether you are looking to nurture vegetables, fruits, flowers, or any other plant type, the PRO-MIX HP Open Top Grow Bag is the ideal choice to elevate your gardening game.



  • Time and cost savings: The PRO-MIX® HP® Biostimulant Open Top Grow Bags require less labor, quick setup, and easy handling. With no container required and a tear-off opening, the grow bags offer a cost-effective solution for plant cultivation.
  • Cleaner: The open top grow bags decrease the risk of handling contamination and eliminate the need for cleaning or sterilization, providing a cleaner environment for plant growth.
  • Adapted: The same PRO-MIX® HP® formula is used in the open top grow bags, providing good drainage capacity, high air porosity, and lower water retention. This makes it easier for roots to breathe and helps to promote healthy root development.
  • Ready-to-use bag: The grow bags come with eight pre-made drainage holes and a unique design that promotes root development, allowing for improved leaching of fertilizer salts during the crop cycle. The ready-to-use bags eliminate the need for any additional setup, saving you time and effort.

Cronk Nutrients #1 Recommended Peat-Based Growing Medium:

Pro-Mix HP is a premium, high-porosity growing medium that is compatible with a variety of plant types and growing systems. Whether you're growing in containers or raised beds, using drip irrigation or hand watering, Pro-Mix HP is the ideal choice for healthy plant growth and development. pH-adjusted for optimum growing conditions, Pro-Mix HP is also compatible with all Cronk Nutrients, ensuring consistent and reliable results with every use.



  • Canadian sphagnum peat moss (65-75%)
  • Perlite - horticultural grade
  • Dolomitic and calcitic limestone (pH adjuster)
  • Wetting agent

Active Ingredients:

  • Bacillus - PTB180 Technology, Bacillus pumilus
  • Mycorrhizae - PTB297 Technology, Glomus intraradices

Bacillus stimulates root hair proliferation for better nutrient absorption and faster growth. Mycorrhizae expand root growth, enhance nutrient uptake, and reduce transplant shock. Canadian sphagnum peat moss and perlite improve air porosity and drainage, while dolomitic and calcitic limestone adjusts pH and provides calcium and magnesium.



Cronk Nutrients' online store ships all over Canada and the United States from Canada & the United States. If your country isn't a standard option, please contact us and we can get a shipping quote. We offer free shipping on any order in North America over $125* We ship via UPS, Purolator, FedEx, Canada Post or from our inventory at either or 

All orders are processed within 1 business day. 

Your order will be marked as fulfilled from the moment it’s been boxed up in the warehouse awaiting for the courier to pick it up. Once your order has been fulfilled, you will receive an email with your tracking number. Your tracking details will appear once the courier has processed the package.  CLICK HERE for more information about our shipping policy. 


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Pro-Mix HP Mycorrhizae Open Top Grow Bag Video



  • Less labor
  • Quick set-up
  • Easy to handle
  • No container required


  • Decreased risk of handling contamination
  • No cleaning or sterilization needed
  • Cleaner environment


  • Unique design which increases root development
  • Improved leaching of fertilizer salts

Bringing PRO-MIX® HP® in a fully adapted solution for your grow tent

PRO-MIX® HP Open-Top Grow Bag
Bullet image 1 PRO-MIX® HP® provides a great growing environment to growers looking for a significant drainage capacity, increased air porosity, and lower water retention.
Bullet image 2 Includes 8 precut drainage holes to avoid overwatering plants.
Bullet image 3 With its light color and breathable material, the bag itself is designed to promote root growth and expansion.
PRO-MIX® HP Open-Top Grow Bag



Shake the bag to gently unpack the growing medium


Tear the removable part of the bag


Transplant directly in the bag, avoiding compaction