House & Garden CalMag is a dry soluble calcium and magnesium fertilizer designed to encourage rapid growth by delivering these key nutrients to your valuable crop. It is also the main nitrogen source for the 3-part House & Garden dry soluble program. CalMag is used with House & Garden Grow throughout the vegetative phase, and House & Garden Bloom during the flowering phase.

House & Garden CalMag can also be used as a supplement with other nutrient regimens and is highly recommended for use with reverse osmosis water and when growing plants in coco coir.