Hi, Choochoo.
to ATP!
All environmental concerns aside, if you have a good soil management program in place it's highly likely that you don't need to add chemicals to your in-ground perennial plants and their soil. When I think of feeding perennial plants, I first consider what will be most likely to benefit my soil organisms, since they'll be instrumental in keeping my plants happy and healthy for many, many years. Chemically altered products wouldn't be my first choice for this.
There are also spray-on, living organism-friendly products that are now widely available that contain micro-nutrients, which, if your plants are already thriving, is all they might yet need.
