Irises: dividing iris will they bloom, 0 by irisguy2

irisguy2 wrote:
I was always told to wait about four to five weeks after bloom time to dig and separate. That way after they bloom, the iris can grow their increases and they can develop roots. In my experience, here in southern Minnesota (zone 4), you can start dividing after the fourth of July unless it is a late year for blooming as this year was. Also, when you divide, replant them immediately after you amend the soil (I use lots of compost, garden lime and alfalfa pellets). Don't let the roots dry out at all. If you pick a few of the largest increases and give them some room to grow, I usually get bloom on most of them a little bit late the following year. If you wait until late August or September here, they may survive the winter but probably won't bloom until after two years. I think the idea of having duplicate clumps and only digging one is a great idea. Some iris cultivars just take time to reestablish themselves (orange and pink ones usually). Typically I find that a newly planted rhizome needs to grow five or six leaves before they are large enough to bloom.