Someone told me that I should fertilize my peony in late Sept. Should I do it now or wait till Spring? Thank you for enlightening me.
Fertilizing anything in late September is not very economical. Much of the fertilizer will be lost by winter rains and most plants are not actively taking up nutrients. Some people use a high potassium feed late in the season (say, early September) to help "harden-off" the plant for its winter rest. I wouldn't worry about fertilizer. Peonies are slow to bulid up reserves and to flower heavily, but they are known to be very long-lived and productive in normal garden soil. The most important consideration may be your own patience.
