PRO-MIX® BX, PRO-MIX® HP® and PRO-MIX® MPX: Understanding the Differences
Selecting the right growing medium is a key decision in ornamental production. While PRO-MIX® BX, PRO-MIX® HP® and PRO-MIX® MPX share the same high-quality peat base, each is formulated to deliver a different balance of water retention and air porosity, which influences dry-down rate, root-zone oxygen content, and how forgiving the substrate is under your irrigation conditions.
Quick guide: which one should you choose?
- PRO-MIX® BX has a dependable, well-balanced air-to-water ratio that works well for a wide range of crops and conditions.
- PRO-MIX® HP® offers high air porosity and low water retention for faster dry-down and easier water management.
- PRO-MIX® MPX offers high water retention to help support steadier moisture and potentially longer intervals between irrigations.
PRO-MIX® BX: Balanced, General-Purpose Performance
PRO-MIX® BX is designed to provide a balanced air-to-water ratio, making it suitable for a wide range of ornamental crops.
Its water-holding capacity supports consistent moisture availability while maintaining enough air space for healthy root development. This balance makes PRO-MIX® BX a reliable option across different production systems.
Typical applications:
- Mixed crop programs
- General greenhouse production
- Situations where a stable, predictable substrate is required without frequent irrigation adjustments.
PRO-MIX® HP®: High Air Porosity and Low Water Retention
PRO-MIX® HP® is formulated for growers who require greater control over moisture levels in the root zone.
With a higher proportion of coarse perlite, PRO-MIX® HP® provides increased air porosity and faster drainage compared to PRO-MIX® BX. This results in quicker dry-down between irrigation events and improved oxygen availability to roots, which is especially helpful when the overwatering risk is higher.
Typical applications:
- Water-sensitive crops
- High-density production.
- Situations where excess moisture must be carefully managed, such as low-light periods or cooler seasons.
PRO-MIX® MPX: High Water Retention and Reduced Irrigation Frequency
PRO-MIX® MPX is a multi-purpose medium designed to retain more water and support a more stable moisture profile over time.
Its water retention capacity helps maintain consistent hydration in the root zone. This can be beneficial for growers aiming to optimize water use, support uniform moisture availability, or reduce labor associated with very frequent irrigation.
Typical applications:
- Crops that benefit from steady moisture conditions
- Production systems where irrigation intervals are longer
- Crops that have high water needs
- Ideal for summer or low humidity, where extra water retention is preferred
Comparing the Three Options
Each product is designed to support a specific irrigation strategy, allowing growers to select the medium that best fits their production approach.
| Feature | PRO-MIX® BX | PRO-MIX® HP® | PRO-MIX® MPX |
|---|---|---|---|
| Air porosity | Medium | High | Medium |
| Water-holding | Medium-high | Low | High |
| Dry-down speed | Medium | Fast | Slow |
| Best fit | Broad use / general programs | Precision irrigation / avoid excess moisture | Maintain steadier moisture / fewer irrigations |
| Common use cases | Mixed crops, general production | Water-sensitive crops, cool/low-light conditions | Longer intervals, stable moisture targets, high light and warm conditions |
Available with AGTIV® Biologicals
All three growing media are available with mycorrhizae. PRO-MIX® BX and PRO-MIX® HP® are also available with Bacillus and mycorrhizae
These biologicals act directly in the root zone to enhance plant performance.
- Mycorrhizae form a symbiotic association with plant roots, extending the effective root system through a network of hyphae. This expanded network improves access to water and nutrients, supporting better yield, quality, and uniformity.
- Bacillus forms a biofilm around the roots and secretes biostimulant molecules, promoting a healthy and conducive growth environment.
Bacillus and Mycorrhizae contribute to more resilient root systems, which are essential for consistent crop performance in ornamental production.
Making the Right Choice
The best option depends on how water is managed in your operation, your crop sensitivity, and your environment.
- If you want a versatile, general-purpose medium with a balanced profile: PRO-MIX® BX
- If you need faster dry down and more air porosity for low light, humid growing conditions: PRO-MIX® HP®
- If you want high water retention to help maintain steadier moisture: PRO-MIX® MPX
Selecting the appropriate medium helps align substrate performance with your irrigation strategy, supporting more consistent ornamental crop outcomes.
Need help selecting the best mix for your crop and irrigation strategy?
Contact your PRO-MIX® representative to discuss your program and conditions.
