Question: I received several clumps of Siberian irises from a friend last spring. I didn’t plant them right away, but when I finally did plant, I watered them well and added some fertilizer. They looked a bit limp for awhile and finally recovered, but they didn’t bloom. Should I expect blooms this year?
Irises are among the season’s loveliest flowers. The big, beautiful bearded irises that are putting on such a show right now seem to be unconcerned about when and how often they’re moved and usually bloom without fussing. But according to the American Iris Society, Siberian irises don’t like to be disturbed once they’re established, so they may sulk for awhile when they’re moved. If the roots dried while they were waiting to be planted, that may have dealt them another blow. AIS cautions that the roots should never be allowed to dry out while they are out of the ground, and they should be watered heavily after they are transplanted.
Last year, the newly planted irises may have spent the spring and summer getting a strong root system established. By this year, you may have a few blooms.
In general, here is what Siberian irises need to do well: slightly acidic soil in a sunny location (though AIS says they can tolerate light shade), and regular moisture. While the rhizomes of bearded irises should be planted almost on top of the soil, Siberian and other beardless varieties should be set slightly deeper in the ground. All beardless irises should be fertilized regularly.