'Immortality' is one of the most
popular and reliable reblooming
irises.

Reblooming Iris Basics

When summer's lush greenness gives way to the sunset hues of autumn, you'd expect the garden to overflow with asters and chrysanthemums. But bearded iris? How did this flouncy flower of spring transform itself into an autumn beauty? Obviously, these aren't ordinary irises. These are reblooming irises, and they're changing the look of fall gardens.

In spring, it would take a trained eye to spot any differences between reblooming irises and the more common once-blooming varieties. Both types flaunt sweet-scented fleurs-de-lis over a fan of leaves. But while most irises sit out the summer, rebloomers multiply in a frenzy of growth. By late summer or fall they're ready to flower again. Where the growing season is long enough, reblooming irises are known to squeeze in a third or even a fourth flush of flowers.

Related Slide Show: Top Reblooming Iris

Although commonly called rebloomers, there are actually several types within this category, according to the Reblooming Iris Society:

• "Rebloomers" (also called "remontants") are irises that produce two or more flushes of bloom each year.
• "Cycle rebloomers" produce a spring crop of flowers, then lie low during summer, and grow and flower again in the fall.
• "Repeaters" produce new flowers soon after the first spring flush dies back, extending the bloom season to one to two months.
• "All-season rebloomers" produce flowers irregularly throughout the season.

There are two "catches" to this classification system: first, most retailers will simply say that a variety they carry reblooms, not what type of rebloomer it is. The other catch is that there are no guarantees that any particular variety in any particular setting will behave in any particular way. That said, most of the irises labeled as rebloomers by reliable suppliers will give you far more "bang" for your flower buck.

In general, the reliability of rebloom declines as you go farther north. Gardeners in Zones 3 and 4 may see little or no reblooming. (The exception is the variety 'Immortality', which is reputed to rebloom as far north as Zone 3.) In most varieties, the reblooming cycle is set off by cooler weather, so if your temperatures are tropical year round, you may not see a second bloom. Also, some varieties will not start reblooming for a couple of years, so patience is a virtue.