Hello Gardeners, I’m Amanda McNulty with Clemson Extension and Making It Grow. Controlled release, controlled slow-release or water-insoluble nitrogen fertilizer blends have plant nutrients but in forms that are not all immediately made available to the plants. Typically, the nutrient blends are coated or encapsulated and as that coating ages and is exposed to moisture or reacts to temperature or soil acidity, the fertilizer is released into the soil where plant roots can use it for growth.
This is a far more effective way of "feeding" plants -- the nutrients are available throughout the entire growing season. Instead of making multiple applications of fertilizer, which takes time, equipment, and for large farms uses lots of fuel to power tractors, a single application of a slow-release product can feed a crop for months. We homeowners, too, can save hours and hours otherwise spent side-dressing our vegetable garden or fertilizing our lawns.
