Yes, Ina, when it was first imported here years ago it was the Magical cure-it-all and several major mass producers added it to the potting mixes of azaleas, hydrangeas and others. But, it was not an experiment: they trusted the manufacturer and used the recommended doses in vast numbers of potted plants . With the first warm spell, apparently all of the fertilizer in the granules was released. Losses were 40,000 azaleas, 30,000 hydrangeas and on and on and on. Safer for us that live in climates where it can get very hot is to crush a few granules and mix the content with the upper layers of the mix/soil.