My bearded irises are no longer blooming well. Why?
The bearded irises may need to be divided. Bearded irises should be divided every 3 to 5 years as the plants quickly become overcrowded and don’t bloom well. July or August is the best time to dig, divide, and transplant bearded irises.
Lack of sunlight could be another possibility. Bearded irises bloom best in full sun. (Plants need at least 6 hours of direct sun per day for best flowering.) Plants in partial shade may not bloom well and should be transplanted to a sunny site.