Find Your Ask the Expert: What kind of iris is this?
This house has been in my family for about nine years and this is the FIRST time this plant has bloomed. I believe it’s an iris, but after looking at several pictures, I can’t figure out what kind of iris. Can anyone help me out? Do they always take years and years to bloom? There are others there but the green is only about three inches tall… the same height as nine years ago…
Amy,
From the look of this picture you have a Siberian (beardless) iris which is a rhizomatous type of iris. Although it is a little early for Siberian irises to bloom, it could be a variety called ‘White Swirl’. The only other option I can think of is that it is a Reticulata (Dutch iris) which is a bulbous iris.
Rhizomatous iris have rhizomes as rootstock that are close to the surface of the soil. Bulbous iris have bulbs as storage organs which are plant below the surface of the ground. Siberian iris reach a height between 18″ to 48″ – Dutch iris reach a height of 6″. Knowing this may help you decide which type of iris you have.
As for lack of blooming, if the soil level is completely covering the iris’ rhizome blooming can be inhibited. Lack of proper nutrition and environmental conditions can also inhibit blooming. Although iris can be found in rock gardens, they may not like the pea gravel bed. You might try a fertilizer that is higher in phosphorus than it is in nitrogen. Too much nitrogen can also inhibit blooming.
So even though the leaves have grown up, the top of the bulb still needs to be uncovered? The pea gravel wasn’t put down until 2004 and the leaves had been about two to three inches tall the entire time.
Strangely enough, there was a board there completely shading them for a few months until I remembered to move it. That one had grown to almost five inches! But that was almost two years ago now.
There are four or five in a row there, but I don’t know if they’re rhizomatous or bulbous… is there a way to tell without damaging them?
Amy,
With a rhizomatous iris like a bearded iris or beardless iris, the rhizome still needs to be partially exposed. What zone do you live in? Are the iris leaves green year round?
You can dig up one of the iris to tell if it is rhizomatous or bulbous. You can do this without damaging the plant. Go past the end of the row about 3 inches and with your spade angled toward the iris go down about 8 inches and pop the iris up. Brush the dirt away and look at the roots. Are they attached to something that looks like a bulb or something more tuberous?