I have 25 peony bushes (the older varieties) that are flowering every year... when should I fertilize them & with what? On the farm they (were over 50 yrs. old!) just got an early spring dressing of cow manure but not having cows (!) here in the city, what commercial fertilizer should I use,what N-P ratio (I'd assume a higher P than N?)& when to apply.

I tried several locations here in my Albuquerque yard with poor results til I found a place shaded a bit by a small Iowan Staghorn sumac tree & all are doing great. But I noticed this year the flowers aren't as big & some later buds never open up .. just dry up. Of course, in this more arid climate than Iowa, the fragrance isn't as lovely as in Iowa either!