Hello fellow iris lovers,
I have several varieties of tall bearded iris, and unfortunately, for the past couple years they have put out green growth but have not put out any blooms. What could I be doing wrong? They all bloomed the first year that I had them. Is it because I don't trim the spent leaves after the growing season has passed? Is there anything else that I might be doing wrong?
Thank you in advance

Perhaps they are planted where they are not getting 6 hours of sun daily. Overcrowding, boreres and rot might also contribute to a lack of bloom.

No, don't trim off green parts. Green parts are making food in order to form next year's bloom buds.

Overcrowding, fertilizer, water...

Consider also that it seems that some irises may not bloom every year, even if given ideal conditions.

Yes, in Tx you might likely need to give them extra water.

In addition to the things mentioned, too much nitrogen in the soil can also contribute to good foliage and poor bloom.

Tom, related to that, I think maybe from now on I will fertilize all clumps that have 3 or more fans with 5-10-10, and all clumps with only one or two fans with 10-10-10. I'd be interested to know if anyone has tried that.

Tom, related to that, I think maybe from now on I will fertilize all clumps that have 3 or more fans with 5-10-10, and all clumps with only one or two fans with 10-10-10. I'd be interested to know if anyone has tried that. I have about 8 newer cultivars that are just hanging in there with only one fan, and 6 more with only two. I'm so afraid they might bloom out before they have a chance to become established.

I always use a balanced fertilizer, one with all three numbers the same. 10-10-10 if I can find it, but the last few years I could only find 13-13-13. So I used that, just not as much. Joe Ghio had recommended that a few years ago in his catalogue, so I've been doing that since. It's worked just fine.
Many years ago in my less then wise younger days, I put some high nitrogen lawn fertilizer on my flower beds, I only had a few irises then, but holy smokes, they sure made some huge clumps of leaves. No blooms for 2 years though.

My local iris society also recommends a balanced fertilizer. I get a slow-release 10-10-10 from Amazon. Other members use 15-15-15 or 16-16-16 which I think they get from Home Depot.

I've wondered whether the post-bloom fertilizer should be a low-nitrogen fertilizer. At that point, the plants are no longer putting out leaves, they are just developing the buds for next year. At least, that is my understanding. Then, the fall fertilizer should be a balanced one again as the rhizomes are putting up increases. (I am adopting a program of fertilizing on Valentine's Day, Memorial Day, and Labor Day.)

Yikes, there are only so many fertilizers I can store. I use some combo of triple phosphate, Osmocote time release, and/or a 10-10-10, depending on the circumstances. (Triple phosphate when dividing or planting new rhizomes. Maybe a top-dressing of mixed 10-10-10 and Osmocote in the fall, or else just the 10-10-10.)

Thanks for specifically tying fertilizer times (in our area) to holidays, Andrea! I knew about the Valentine's Day thing in spring, but post-bloom? And fall is whenever...

I agree = when planting new rhizomes, stir in triple phosphate or bone meal in the hole and then sprinkle a balanced fertilizer on the surface around the plant.

I made the mistake of making my own fertilizer mix this year and ended up with a much lower yield of blooms than in years past. And yes, lots of leaves. In the past, I would use 5-10-10, but this year I tried to make my own 10-20-20. Well maybe that 10 really kicked in cause I got leaves, whole gardens of them.
But that brings up a question for you Iris experts. When did this years blooms get created? At the end of last Spring or early this Spring or both? I may be blaming this year's fertilizer when it was really something I did last year.

I have always read that the new blooms get initiated way down in the rizomes of the new starts in the six weeks following bloom of the mother rhizome, and that's why one should fertilize after bloom with a fertilizer that is higher in phosphate than it is in nitrogen. The first number is nitrogen, and you doubled it. That probably threw a lot of energy into leaf production.

But it's probably more how you treated them last june and july that affected bloom this year. And are they getting enough sun?

Thanks for the advice Daisy. That will give me the motivation to fertilize a second time this Spring. I did also try cutting back watering a bit last Summer after they went into hibernation and maybe I cut back too much. Also I didn't fertilize last Fall and I usually do but I have done that before and it didn't usually impact this much.
I will go back to a 5-10-10 fertilizer. And start fertilizing twice in the Spring and once in the Fall. I think my aging garden needs it!

Also, if your clumps are getting crowded, they won't bloom as well, especially the most crowded new starts in the center of the clump.