There are six types of reblooming iris:
- ·rebloomers or remontants bloom more than once in a season. Iris classifications with rebloomer characteristics: Miniature Dwarf Bearded, Standard Dwarf Bearded, Intermediate Bearded, Miniature Tall Bearded, Border Bearded, Tall Bearded, and beardless varieties.
- ·cycle rebloomers bloom spring and again either late summer or fall. The second bloom occurs on maturing increases and does not require vernalization; however, cooler nights encourage rebloom.
- ·repeaters are beardless varieties that rebloom. Repeaters rebloom from old growth immediately after spring bloom. Rebloom is sporadic from year-to-year. However, repeaters may extend the blooming season 1-2 months.
- ·all season rebloomers rely on soil temperature rather than day length to encourage rebloom. Bloom may occur anytime throughout the season on either mature or newly matured growth.
- ·rebloom carriers bloom only in the spring and does not rebloom, but seedlings will rebloom if crossed with a rebloomer.
- ·occasional rebloomer are cultivars that have a sporadic tendency to rebloom.
Rebloom is affected by weather conditions, cultural conditions, zonal location, and how well established the iris is.
- ·weather conditions that are extreme, i.e., hot summer nights and frigid winters, encourages dormancy and halts rebloom.
- ·cultural conditions that encourage rebloom include preventing irises from drying out by watering them to encourage good growth (at least once every other week when rainfall is inadequate). Extra application of fertilizer (50/50 mix of 5-10-5 and 0-45-0) in early spring, after spring bloom, and applying liquid foliar fertilizer once or twice in September to promote rebloom.
- ·zonal location affects rebloom. The reblooming cycle is triggered by cooler weather. So they may only bloom once dependent on zonal weather conditions. However, the zonal location is only a guide, sometimes a microclimate can have rebloom within a zone.
- ·how well established the iris is also affects rebloom. Some rebloomers may need to be established for one to two years before reblooming, and others are very sporadic when reblooming.
With the possibility of 2, 3, or 4 reblooms in one season, dependent on zonal location and cultural care, rebloomers may extend the bloom in your garden!