All Purpose 20-20-20 is considered the industry standard of general purpose fertilizers by professional growers. It feeds both through the roots and the leaves. This formula of nitrogen, phosphorus and potassium provides fast green-up and rapid leaf expansion. Recommended for use on all your indoor and outdoor plants. Indoors it is especially effective on foliage plants, keeping leaves green. A proven performer in the vegetable garden for generations, this product may be used in combination with Jack’s Classic Blossom Booster giving your plants greener leaves, more flowers and brighter colors.