Ammonium sulfate is an acid forming fertilizer that contains 21% nitrogen and is good for the alkaline soils of Parker County. It also helps maintain or can help reduce the pH in your soil.
Other elements are tied up when the soil pH shows high alkaline levels and in our area, it can be an advantage to reduce the pH level. It is a low rate of nitrogen therefore there is less chance of foliar burn. However, anytime you apply fertilizer to grass you should then water your lawn.
This applies for shrubs as well as all the landscape.
-- Special thanks to Dr Jerral Johnson, Professor Emeritus Dept Plant Pathology and Microbiology, Texas A&M University