Fertilome Root Stimulator uses the hormone Indole-3-butyric Acid and an NPK of 4-10-3 to quickly maximize root growth and provide nutrition to get your plants off to a strong start. Use this product every time you plant or transplant to stimulate early and strong root formation and promote greener, stronger plants. For use on trees, shrubs, roses and other flowers, houseplants and annuals. This solution is a root stimulant and should not be applied to plant foliage as a fertilizer or plant food. Shop all Fertilome products here .