Jobe's(TM) Fertilizer Spikes for Azaleas, Camellias & Rhododendrons are specially formulated to fertilize acid-loving plants. Unlike surface applied fertilizers that can wash away with rain or watering, Jobe's works underground at the roots. Nutrients are slowly released where plants get their nourishment, providing your acid-loving plants with healthy growth and beautiful blooms. The specially formulated, premeasured spikes make for a fast, easy and mess-free fertilizing experience. For best results, apply just after blooms shed, usually late spring or early summer. Spikes come in a waterproof, resealable pouch.