16Oz Hydrangea Fertilizer – Makes 16 Gallons of Hydrangea Plant Food, Hydrangeas Indoor Plant Fertilizer Liquid for Lush Growth, Strong Stems, and Vibrant Blooms, Nutrient-Rich Flower Food. FOR ALL HYDRANGEAS: Works as a flower fertilizer and fertilizer sprayer, HiThrive liquid plant food ensures steady growth & breathtaking blooms for Bigleaf, Oakleaf, Blue Hydrangea & more.