Sub Bulb Better-Gro Orchid Bloom Booster is a professionally formulated fertilizer, urea-free nitrogen. Contains a high content of phosphorus which is a powerful blooming agent! It's secret 11-35-15 formula was developed by Sun Bulb master growers. Used in their greenhouses to elevate bloom color, boost bloom size and speed up flowering. Orchid Bloom Booster produces vibrant, long lasting beautiful blooms by providing the exact mix of nutrient and ingredients that your orchids need. Apply during every fourth watering. Also contains minor elements essential to combating deficiencies that can occur when using soilless potting mixes. Resealable bag.