Some iris will benefit from being moved to a different location. Some iris are inclined to skip a year every so often. Some iris will nearly bloom out requiring little nubbings to grow for a year to blooming size. Then some iris will bloom every year almost wherever you put them.

The majority of my MDB and SDBs bloom every year, regardless of weather conditions. In good climate years, most of the IBs and MTBs bloom, as well, though they can easily refuse to bloom in difficult climate years like this one. I'm lucky if the majority of my TBs and BBs bloom every 3-4 yrs, even in good weather years. My growing season is just too short for the TBs and BBs to mature their increases to blooming size within a year or two.

Laurie

Would the addition of a good fertlizer help them increase fast in a short growing envirement? I have a very short growing season up here and was wondering the same thing as the poster.

I wanted to bump this for some ideas.

they need absolute full sun ...

ken

I'm new on here! I've been enjoying learning from the posts & love the pics from everyone!
My irises down on my land didn't bloom this year. I had one clump of white ones that did bloom because they were in partial shade. I think the drought from last year made them shut down just to survive. The native cactus down there were even curling up last year, which I have never seen happen before. That's bad! My land is to far for us to go to all the time to water. My irises usually really thrive down there because they love the climate & red dirt. Very sad this year & last year!
Kay

Most of mine do not bloom every year. I admit I have very limited room, and one of my beds is not ideal in terms of amount of sunlight the flowers receive. Still, most flowers in that bed bloom. I think some just need to be divided more frequently. I have a few that are in their third and fourth years, and they still haven't bloomed yet. If not this year, they're going to have to go. Interestingly, one of these is Florentine Silk, which has dominated all the competition in its category in the AIS awards voting. I assume it will win the Dykes whenever it is eligible. It sure doesn't get my vote, though! At least not yet ;)

Mike in north coastal SC (where it is WINDY as all get out today)

Mine bloom every year all Tall bearded.

In my experience tall beardeds need moving to a new place every few years, or providing new soil in the same place.It is as if they make the soil 'iris tired'(for want of a better word).In my Nothern garden I have not seen some of mine for years(but the tags have been stolen by birds, so I do not know what is what until it blooms). Iris that bloom more often than others here up North are: Latin Lover, Spinning Wheel, White Owl, Supreme Sultan, Best Bet, Sultry Mood, Echo de France, Song of Norway, Edith Wolford, Before the Storm, Holy Night,Superstition, Sweet Musette, Starcrest and Olympic Challenge. Some bloom now and then: Vanity, Stepping out, Tut's Gold,Glad Rags. Some have NEVER bloomed and were thrown out: Mystique, New Moon, Kilt Lilt. Some have been tried several times and died in winter: Silverado, Jesse's Song, Fall Fiesta.

Wieslaw59,
How do you throw irises away? I could never do that! Send them my way if you start tossing them out again! :)
Kay

I never heard of iris that wouldn't bloom. As far as I have experienced in over 35 years of gardening, put an iris in full sun (I was always told, the hotter the better), don't plant them too deep, and for tall bearded iris, keep them on the drier side after they are done flowering. As far as my iris were concerned (in 4 different states), that's all they needed to bloom. Of course, I've only grown tall bearded iris and Siberian iris.

I rarely dig them up to thin them out, except for one older tall bearded iris that multiplies so rapidly that the corms start growing on top of each other. With other irises, I sometimes pull some out around the edges because they want to spread beyond their allotted space. If nobody else wants them, I throw them away.

To me, irises are the easiest flowers in the world to grow. I wouldn't do anything to try to make it more complicated to care for such an easy-care flower.

Kate

Most of mine bloom every year. Some of the newer varieties, though, have never bloomed for me, so I tossed them.

Full sun is the main trick. I divide every few years, and sometimes the rebloomers skip a half a season when I do.
Renee

The rebloomers might have different habits, for all I know. I have never grown them, so my previous comments would apply only to the more traditional once-blooming tall bearded irises.

Kate

Most of them bloom every year. I can tell you that Ritas will bloom every year or get shovel pruned...one of her iris warns every new, and it bursts its buttons to bloom! Right Rita?
kay

I'm much more patient, but I have space to give to slackers, if I like them. Right now 75% of my iris have bloomed. Many of the remaining have buds. Of those that did not bloom, 8 I got 2 years or more ago with no blooms yet :( , but some of those were tiny when I got them from the same trade & didn't expect bloom for a while, although I really did this year. Another 6 or so I just got last year-but some of those are lates & may still bloom. I divided several clumps last year, 3 of those did not bloom-some of the rhizomes were big enough to bloom, but didn't. I'm surprised, but that happens. I do have 2 iris that just don't seem to multiply well & only grow big enough to bloom every other year. This was their year. Batik is an odd one-I got it several years ago, took 3 years to bloom the first time. It bloomed 3 years in a row, then I divided it, didn't bloom 2 years & I moved it again & it still hasn't bloomed. I think once it is settled it will bloom every year. Maybe.

Thanks. I moved mine last June and others last October, and only a few bloomed. (Some were nonbloomers since I moved here, and others came from husband's ancestral home). I figure I will wait until 2013. If they do not bloom then, I am digging up the non-ancestral ones. I do not have much space. I love irises, though, so I hope they settle in and bloom yearly.

Do Dutch irises bloom more often?