FoxFarm Cal-Mag (1 gal)

Gringo Rasta Cal-Mag from FoxFarm is designed to support strong plant structure and healthy yields by supplying two essential secondary nutrients—calcium and magnesium. These minerals play a vital role in strengthening cell walls, aiding in enzyme activity, and supporting fruit and flower development for a more productive garden.

Ideal for use in both soil-based and hydroponic systems, Cal-Mag helps prevent common nutrient deficiencies that can lead to issues like blossom end rot or poor bud formation. Its formula is OMRI Listed and registered as a CDFA Organic Input Material, ensuring it’s suitable for certified organic growing. Containing 3% calcium and 0.9% magnesium, it’s derived from calcium carbonate, magnesium sulfate, and soy protein hydrolysate for efficient nutrient uptake.

Whether you’re growing vegetables, fruits, or flowering plants, this supplement can be a valuable part of your feeding program to promote overall plant vigor and resilience.

For more soil health and plant nutrition products, explore our Fertilizer & Growing Supplies collection.

• Size: 1 gallon
• Calcium Content: 3%
• Magnesium Content: 0.9%
• Suitable For: Soil and hydroponics
• Organic Certification: OMRI Listed, CDFA Organic Input
• Derived From: Calcium carbonate, magnesium sulfate, soy protein hydrolysate

How FoxFarm Cal-Mag (1 gal) fits a fertility plan

• Supplies calcium and magnesium for fertility programs where soil, water, tissue testing, or a well-supported diagnosis indicates a need.
• A nutrient-specific amendment allows more precise correction than adding another broad, complete fertilizer.
• The package size and dry or liquid format shown in the title can be matched to the application equipment and growing area.

Application guidance: Confirm that calcium and magnesium availability is actually limiting before application; pH, root health, salinity, and overwatering can produce similar symptoms. Follow the label rate and placement method, measure carefully, and avoid repeated applications without retesting. Nutrient excess can interfere with uptake of other elements.

Compare related secondary and micronutrient fertilizers when building a complete program.