Epsom salts or magnesium sulfate are an excellent source of both magnesium and sulfur. Many gardeners religiously use Epsom salts for rose growth. Epsom salts result in greener and fuller foliage with abundant blooms that are beaming with color and scent. An ideal mix is a tablespoon of Epsom salt in a gallon of water. You can spray this solution directly onto the soil. Alternatively, you could go ahead and follow an organic mix recipe if you prefer. Prep your soil by watering your roses. Add a mixture of 110 grams of Epsom salt, 230 grams of fish meal, and 110 grams of bone meal. Sprinkle generously and follow with watering. This will allow the Epsom salts to dissolve and be readily available as a solution for absorption by the rose plant roots.