SoundGRO is a slow release fertilizer with a very low salt-index compared to traditional chemical based fertilizers. The nitrogen in SoundGRO is broken down by microorganisms in the soil before being absorbed by the plant. Slow-release prevents initial growth spurts in plants. It also ensures that the fertilizer works over a longer period of time, reducing the number of fertilizer applications required in a year. SoundGRO does not need to be watered in.