Extend the iris season with types that flower more than once per growing season.
Love iris flowers? Give your garden an extended iris season by planting reblooming iris. These perennial beauties hold their own with an eye-catching show during the normal iris flowering window, but then follow up with additional blooms later in the growing season. Reblooming iris require a little extra TLC to help them put on their twice-as-nice flower show, but the extra effort pays off.
Reblooming iris fall into several groups. Most of them are bearded iris, but there are some reblooming Japanese and Siberian iris, too. Some reblooming iris produce two or more flushes of flowers each growing year—these are called rebloomers. Another group is referred to as cycle rebloomers. These reblooming iris flower in spring, rest during summer and deliver a second floral display in fall.
A group of reblooming iris called repeaters flower in spring and immediately send up new blossom stems after the first ones fade. The last group of reblooming iris are the all-season rebloomers, which can produce flowers at any point throughout the growing season.
The most important thing to understand about reblooming iris is that nothing is guaranteed. Reblooming may or may not occur, even in named reblooming varieties, depending on things like growing conditions, plant age, zone and available water. Some reblooming iris need to grow for a few years before they can start pumping out those subsequent flower flushes.
Generally speaking, reblooming iris are less reliable in their multiple flower flushes the further north you grow. Most reblooming iris are reliable rebloomers in Zones 5 to 10. Zones 3 and 4 are where rebloom becomes more iffy.