If you've never grown a Reblooming Iris or have had mixed results with other varieties, we suggest you try 'Immortality', for it rarely disappoints. After mounting a good show in June, it produces a second crop of pristine white flowers in late summer almost every year and in almost every climate (it even reblooms in Zone 4). It's also a great garden plant. Hard to beat.
There is a small but growing number of Bearded Iris that bloom gloriously in June, then flower again in late summer and into fall. They have no requirements beyond a light dose of fertilizer once the first bloom is complete and regular watering when things get hot and dry. This small effort is amply rewarded as the season draws to a close.