Any idea why my iris won't bloom?

polly and dee, I'm going to keep learning a LOT from y'all!

Mittsy, that iris you are testing in the picture looks like my Dauntless; does yours have PBF?

The idea that some iris don't bloom for years is totally new for me. For the last 30 years, wherever I've lived, I have had iris. They were simple to grow and always looked spectacular right off the bat! So when I moved to this house last year, I ordered some from a reputable grower in OR. I have ordered from them before and always been happy. When they arrived, they looked great and I planted them in new, freshly amended beds. This spring, the leaves look great.

As for blooms, the ones that did so look gorgeous! But over 1/2 didn't bloom at all. For instance, I planted 2 rhizomes of the same variety 2 ft apart. One is so pretty and the other is a healthy clump of leaves. This is very surprising to me. I keep trying to figure out what I did wrong. Now I read the suggestion that some iris bloom only with the arrival of the cicadas! lol

One variable is that DH insisted on putting down mulch, which I push away from the plants. I do have issues with shade. But I chose the sunniest places. And being so close to each other with different results suggests it's not the sun, shade, or soil. Could it be that some rhizomes are "sitting this one out" and will bloom next year?

Any suggestions? Anything I might try rather than just waiting for next year? I will try adding phosphorous-rich food.

I have had some iris that were lurking in shady corners that never bloomed - maybe because they were isolated they didn't succumb to iris borer? (Or maybe some of them did, but who would know? - If they lived the foliage became over crowded, but no blooms.

at the AIS nationals, in judges training, I learned something new to me - a healthy "prime" iris clump only blooms on about 25-30% of it's rhizomes. if more than 50% bloom, you may experience "bloomout." if fewer than 25% bloom, it's stressed or a problem child.

and I can tell you from experience, because NC is heavily forested statewide, anything less than 6 hours of sun, you will not get good bloom, only foliage. it takes a ton of energy to bloom, provided by sunpower.

Sometimes the shade creeps up on you before you realize it. Something that got full sun several years ago may not get enough because of rapidly growing tree branches, shrubs, etc.

Well as I said I had one iris that took 4 years to bloom and the rhizome was normal size, planted full sun no mulch now that it has bloomed it is going to compost...As I do not like it at all. Most iris will bloom every year, some will take a year off, on the whole most will bloom at least every other year and that is pushing it.

Iris hate mulch such as bark, mushroom etc, they do not mine Pine Needle, but we do not have alot here on the place. Out of 1400 varieites this year, first year in the new spot only 10% did not bloom. Planted in full sun, fertiliezed twice with low nitro, keep almost totally weed free. The water to date has been from old Ma Nature which is above normal even for the PNW...

D

Pine needles for mulch sounds like something I could use. What about the pine cones? I could pick up bushels of them and have used them as "mulch" around certain plants, and to add an element of texture in a limited area. I have a lot of low hanging pine branches that need to be trimmed so we can mow under them. I could probably just pile them to save for iris mulch for the new iris I will be planting? It wouldn't matter if the needles fell of onto the irises, right?

Denise, just out of curiosity, how many irises do you grow, and how close do you plant them? Do you have an iris field, like a corn field, with rows of irises? We vacationed in Louisiana this spring, and I saw sugar growing for the first time. They grow them in raised rows that reminded me of the way I plant my iris.

We use pine needles as a winter mulch once the ground is frozen to help guard against alternate freezing & thawing. It is removed in April for the summer.

I'm going to jump in here, because I HAVE pine needles, compliments of mother nature, and they DO MIND a LOT of pine needles LOL it's not that they don't grow, but they don't seem to make very big clumps. in my naturally mulched with pine needles bed, only Mulled Wine has made a decent clump in 2.5 years, out of 22 irises.

and if you have acidic soil, like we do, they increase the acid ever so slightly, so it's even more important to put down lime.

planted roses and reblooming iris in a bed together, and mulched with mini pine bark nuggets because the roses like them best. Those irises are doing well, too.

Our needle mulch is quite light & removed in the spring. The iris may not like the mulch the yr around. 6.5 soil in our garden.