Houseplant Special 15-30-15 is our traditional indoor houseplant fertilizer designed for use on all foliage and flowering plants. Professional growers prefer the 1-2-1 ratio fertilizer used for over 50 years to keep indoor grown plants vigorous and green. Great for long term plants! Used in a constant feed system, it keeps the nutrition levels constant preventing nutrient stress from over or under feeding. This product can also be used outdoors as a transplant solution and as a blossom booster for all flowering plants.