5:1 Cal-Mag (Coarse)
A slow-release calcium and magnesium amendment designed for long-term soil building and cation balance. Ideal for pre-plant applications, soil blending, and outdoor systems where stability over time is more important than rapid adjustment.
This coarse blend of limestone and dolomite is formulated at a 5:1 calcium to magnesium ratio and is intended to work gradually within the soil, supporting structure, nutrient availability, and overall system balance across multiple growing seasons.
The larger particle size breaks down slowly, providing a steady release of calcium and magnesium over time. This supports a consistent background supply while reducing the risk of over-application compared to finer, fast-acting materials.
⚖️ Why Calcium and Magnesium Balance Matters
Calcium (Ca²⁺), magnesium (Mg²⁺), and potassium (K⁺) interact continuously in the soil and at the root surface.
- Calcium supports soil aggregation, pore space, and water movement
- Magnesium supports chlorophyll production and overall plant function
Maintaining a calcium-forward balance helps support soil structure while keeping interactions between Ca, Mg, and K more stable over time—especially in systems where nutrients are actively cycled and reintroduced.
🔄 Designed for Long-Term Systems
This product is best suited for growers managing soil over multiple seasons rather than making quick adjustments. It works particularly well in:
- Outdoor cannabis and large-scale growing systems
- In-ground beds and permanent growing areas
- Orchards, vineyards, and perennial fruit systems
- Soil building and long-term remineralization programs
In these systems, coarse materials act as a slow mineral reserve, supporting long-term calcium and magnesium availability while helping maintain balanced soil conditions and stable cation relationships over time.
🚫 Not Intended For
- Rapid pH adjustment
- Correcting active deficiencies
- Indoor or highly reactive growing systems
For faster response or precision adjustment, a finer material such as our powdered cal-mag is more appropriate.
Application
Primarily suited for outdoor and large-scale soil systems
Large Garden Areas & Lawns 🌱
Apply 1–2 kg per 10 m² (2–4 lbs per 100 ft²) and incorporate into the top layer of soil before planting or during seasonal soil preparation. Best used during initial soil building or periodic remineralization as part of long-term soil management. Reapply as needed based on soil condition and overall management approach.
Greenhouse & Commercial Growing 🌿
Suitable for soil blending and long-term mineral management in larger systems. Apply during initial soil build or as part of periodic soil maintenance. Use soil testing if needed to guide long-term application rates.
Important Notes
- This is a slow-release material—effects occur gradually over multiple seasons
- Less prone to over-application than fine powders, but slower to influence soil conditions
- Best used as a foundational amendment, not a corrective input
We offer lab soil analysis and can help determine the correct application rate based on your specific conditions.
🌿 Best Use Conditions
- Soils low in calcium and trending acidic
- Systems requiring long-term structural and mineral support
- Situations where magnesium is present but needs to remain balanced with calcium
The 5:1 ratio provides a more calcium-forward alternative to standard dolomite lime, supporting both soil structure and long-term nutrient balance.
Typical Analysis
- Calcium (Ca): 30%
- Magnesium (Mg): 6%
This product complies with Canada’s Organic Production Systems General Principles & Management Standards and Permitted Substances Lists (CAN/CGSB-32.310-2021 CAN/CGSB-32.311-2020)
