Hello Gardeners, I’m Amanda McNulty with Clemson Extension and Making It Grow . When you get a container plant from a nursery, usually you see what looks like tiny plastic balls on the top of the soil. The technical name for these structures is a prill and they are examples of a slow-release formulation, polymer coated fertilizer. Different blends of fertilizer, mostly nitrogen, phosphorus and potassiuim but sometimes with micro-nutrients as well, are coated with varying thicknesses or a