Urban Farm Fertilizers Rose Garden Professional Rose Fertilizer. 1 Gallon. Makes 256 gals. Hand-crafted, Micro-brewed liquid fertilizer for roses. 4-4-3 NPK. Super-concentrated: 256:1. One gallon makes 256 gallons of full strength fertilizer. 100% nutritionally complete, 100% water soluble, precision formulated and blended. Made from organic components, mycorrhizae, humic acid, kelp, enzymes, and minerals. With 4% Calcium! Most people don't realize how much calcium roses need. A lot!