Greenway Biotech Calcium Nitrate 15.5-0-0 supplies nitrogen and calcium together: 15.5% nitrogen (14.5% nitrate, 1% ammoniacal) and 19% calcium, from ammonium calcium nitrate double salt. Spread it dry as a vegetable sidedress, or dissolve it for drip fertigation and hydroponic recipes. Clemson and University of Georgia Extension call a calcium nitrate sidedress usually the best choice for tomatoes, at 2 lb per 100 feet of row applied monthly, and Clemson gives weighed calcium nitrate rates for peppers, okra, cucumbers, squash, melons, and cole crops. In a nutrient solution, 1 gram per liter adds 190 ppm calcium and 155 ppm nitrogen, so count that nitrogen in your recipe and keep its concentrate separate from phosphate and sulfate stocks. It is not a complete fertilizer or a cure for blossom-end rot; steady watering matters as much as the fertilizer. Measure it by weight. Packed in Madera, California, in 2 to 50 lb sizes.
