House & Garden CalMag 12-0-0 is a soluble dry fertilizer supplying nitrogen, calcium and magnesium in a 25 lb package. It is the CalMag component of the House & Garden dry three-part base program, paired with Grow during vegetative growth and Bloom during flowering.

With 11.9% nitrate nitrogen, 10% calcium and 3% water-soluble magnesium, the powder provides clearly specified nutrient inputs for growers managing a staged feeding program. Measure by weight and use the manufacturer's chart to select the appropriate rate for your crop stage.

Guaranteed Analysis

• Total nitrogen (N): 12.0%
• Ammoniacal nitrogen: 0.1%
• Nitrate nitrogen: 11.9%
• Calcium (Ca): 10.0%
• Magnesium (Mg): 3.0%
• Water-soluble magnesium: 3.0%

Derived from ammonium calcium nitrate double salt and magnesium nitrate.

Rates in the Manufacturer's Dry Three-Part Feed Chart

The following CalMag rates are per 1 U.S. gallon of RO water as part of the combined House & Garden program. They are not a standalone feeding recommendation for every crop or water source.

• Cuttings and seedlings: 2.6 g
• Vegetative week 1: 4.5 g
• Vegetative week 2: 5.2 g
• Flowering week 1: 4.4 g
• Flowering week 2: 5.0 g
• Flowering week 3: 5.4 g
• Flowering week 4: 6.1 g
• Flowering week 5: 5.9 g
• Flowering weeks 6–8: 5.0 g

Use the complete chart for the accompanying Grow or Bloom rates, optional additives and combined nutrient-solution EC targets. Follow product labels and adjust feeding to crop needs and source-water quality. Do not apply dry powder directly to growing media.

Feed Chart Download

Download the House & Garden 8-Week Dry 3-Part Base Feed Chart (PDF)

Handling and Storage

Keep out of reach of children. Not for internal use. Avoid contact with skin and eyes and wear suitable protective clothing during handling. Keep the container sealed and dry. Follow the product label and safety data sheet for handling and storage requirements.