P 7%. Bat Guano Bloom is a great immediate-release source of natural phosphorous. It's best to add prior to and during blooming. It can be steeped in water and used as a plant tea and foliage spray. For container plants, use from 2-8 tablespoons per gallon of soil. For gardens, use 10 lbs per 100 sq ft. For trees, use 1/2-2 cups per foot of tree height. 5 lb minimum order.