Dual Cal is a specialty powder blend designed to provide a balanced, dual-source calcium supplement for cannabis plants. Its formulation combines calcium sulfate (gypsum) and calcium lignosulfonate, offering both immediate and sustained calcium availability to support plant health and soil structure.
Benefits of Each Component
Calcium Sulfate (Gypsum)
- Source of Calcium and Sulfur: Gypsum is a natural mineral that supplies essential calcium and sulfur, both critical for cannabis plant growth and development.
- Improves Soil Structure: It helps loosen compacted soils, increases water infiltration, and reduces runoff and erosion.
- Neutral pH Impact: Unlike lime, gypsum does not raise soil pH, making it suitable for use in soils with balanced or slightly acidic pH where pH adjustment is not desired.
- Reduces Sodium and Heavy Metal Toxicity: Gypsum leaches excess sodium from the soil and helps mitigate heavy metal toxicity, protecting plant roots.
- Enhances Nutrient Uptake: Calcium from gypsum supports the biochemical mechanisms that enable roots to absorb other nutrients efficiently.
Calcium Lignosulfonate
- Chelated Calcium: Calcium lignosulfonate is a chelated form of calcium, meaning it is bound to organic molecules that help protect it from being locked up in the soil and make it more available for plant uptake.
- Slow-Release: This form provides a gradual, sustained release of calcium, complementing the immediate availability from gypsum.
- Soil Conditioning: Lignosulfonate improves soil aggregation and microbial activity, further supporting root health and nutrient cycling.
Breakdown Time
- Calcium Sulfate (Gypsum): Breaks down relatively quickly in moist soil, with most calcium becoming available within days to a few weeks, depending on soil conditions and microbial activity.
- Calcium Lignosulfonate: Releases calcium more slowly, over weeks to months, as soil microbes break down the organic component, providing a steady supply of calcium.
Application Rate for Cannabis
Frequency: Reapply every 4–6 weeks if needed, based on plant response and soil tests. Avoid over-application, as excess calcium can lead to nutrient imbalances
General Recommendation: For cannabis, a typical application rate for gypsum is 1–2 tablespoons per square foot, worked into the topsoil at any stage of plant growth..
How to Apply (e.g., 1 gallon pot):
- Soil Mixing: At planting, blend ½ to 1 teaspoon of Dual Cal powder thoroughly into the potting mix before filling your 1-gallon pot.
- Top-Dressing: If your plant is already established, sprinkle ½ to 1 teaspoon of Dual Cal on the soil surface around the plant, then gently water it in.
- Frequency: Apply once at the start or during soil preparation, and reapply every 4–6 weeks as needed (based on plant health and soil testing).
Timing: Can be applied at any stage—during soil preparation, at transplanting, or as a top-dress during the growing cycle. For best results, incorporate into the soil before planting or apply as a top-dress and water in well.