“Why Did My Iris Take So Long to Bloom? I planted Irises about three years ago & this is the first year they have bloomed. Is that normal?” Question from Rosie of Wichita, Kansas
Answer: I am going to assume you are growing German bearded iris (Iris germanica), the most common iris variety in the United States. There are lots of factors that may have caused yours to be late in blooming, such as small starting size or less-than-ideal growing conditions. Since I am not certain of your plant’s garden conditions, let me simply share what German iris need to thrive.
These popular garden flowers perform best when given full sun and fertile, well-drained soil conditions. (I recommend adding Black Gold Garden Compost Blend if your soil is low in organic matter.) Bearded iris rhizomes should be planted with the tops at or slightly above the soil surface, as those planted too deeply may result in lush foliage but fewer or no flowers. Late spring freezes, which can halt early stem and bud development after the plant has sprouted, are another common cause for lack of flowering in bearded irises. Other factors that might have impacted the delay in blooming are lack of sufficient sunlight, poorly drained soil, or insufficient soil nutrition.
I hope that these insights help. And, if you think there are some improvements that can be made to the growing conditions of your iris, I encourage you to make them. It is always wonderful when iris are in full bloom in spring.
Black Gold Horticulturist.