I wouldn't let the new compost touch the rhizomes.
As for the fertilizer (granules), I only lightly apply it in Spring and after the majority of blooming is done. I work the fertilizer into the soil with a three prong cultivator. In Spring, I will also work some alfalfa pellets into the soil at the same time as the fert. When I plant, I work alfalfa pellets (or bone meal) and some fertilizer into the hole and mix it in.
If I don't work the alfalfa into the soil, the jackrabbits and bush bunnies will have a field day.
