Though it hasn't been a problem for me personally, I thought it might be interesting to see which members that have had experiences with bloom out. The question is if it possibly is climate related and if it is a larger problem in warmer areas? So it would be helpful if we had lots of participants.

So what is bloom out? I found this description in an AIS blog:

"The rhizome increases in size and twists slightly as if it is pushed out of the ground. This could be the result of the roots drying out. Some of the "lightbulbs" bloom. The bloom stalk comes up in the middle of the fan and dies back quickly. The rhizome eventually dries up and dies also."
https://theamericanirissociety...

I'm curious if anyone has noticed that "The rhizome increases in size and twists slightly as if it is pushed out of the ground."?

Possible solutions:

Covering the rhizome with soil or an upside down pot. Question is, does this work and how often is it effective? In some soils and climates this could make the rhizome rot, so obviously one would need to have that in mind before trying.

Cutting the bloom stem. Does this have any effect? Is it better to cut the bloom stem early or perhaps even to cut the fan before any signs of bloom, to conserve energy for new increases?

Possible preventive measures:
In warm climates, is there a chance that deeper planting prevents bloom out? The idea here is less stress, less heat and therefore less bloom and more increases.

So let's see if we can get a discussion going. I realize this isn't a topic with a huge appeal to everyone, but at the very least we perhaps can gather a little info in one place to make it easier to find.

Wow, William. I guess I have never had 'Bloom out'. That is a new description of the term for me and I don't recognize any of those symptoms. Thanks for the information. I will quit telling people that a certain iris I grow has had bloom out. I hope every one reads this.

Bonnie, I would be most interested in what you consider to be bloom out?
There could be several interpretations of bloom out and there could also be a multitude of symptoms. Nothing is necessarily wrong!

The definition I found above is really only meant as a starting point for the discussion and so are all the suggestions.

The term 'bloom out' around here means that during the spring bloom season every fan has a bloom stalk including the new baby rhizomes. This means that every little rhizome in the whole clump is a now mother rhizome and unless the clump grows some new rhizomes, which is not likely as it has spent all energy making many blooms, you will not get any blooms the next year. It does not mean that the iris dies.

I think several of us have been talking about different conditions. Perhaps the definition I refer to is just a local one.

Thank you Bonnie, that was interesting. The bloom out you have experienced seems much more pleasant as it involves the rhizomes survival.

I agree, William. But it does make me wonder if people thought I was mad to tell them not to worry about bloom out.

I had understood bloom out like Bonnie described. I have had that happen only once, then later that fall some increases started to develop.

I have had one seedling that only had one rhizome, it bloomed, then never sent out any increases, so it died. Of course it was a pretty one too.

I've had one or rwo experiences of an iris doing well, blooming spectacularly, then dying out. That's what I thought "bloom out" was.
Looks like I was wrong?

The bloom stalk comes up in the middle of the fan and dies back quickly. The rhizome eventually dries up and dies also.

This is what bloom out means to me. It can happen to a single rhizome, or the clump.

Edited to add:
Wait a minute, maybe I read that wrong. I thought it was as described above, but the stalk(s) still produce their flowers, not die back quickly. Then the rhizome(s) dry up without producing any increase(s).

I was using it in the same since as Jan and Rob I believe. . It burns out because it overproduces flowers and has no energy left for increases.
I had it happen on a 1st season rhizome that looked too small to flower, yet it put out a big bloom. The two I have now that I think may burn out bloomed heavy last year and are trying to bloom again. There is all of one plant in each case.
So yes in the future I should maybe say "burn~out" cause my Rhizomes in these cases are underground and not twisted.

Bloom out is when every fan blooms and that is it. There is no increase since every increase has bloomed. It is also referred to as a bald rhizome. The Mother (the original rhizome blooms) and there is no increase. Digging the rhizome will show no sign of an increase. Nothing you can do will cause it the produce a growth since there is no bud eye. Certain varieties and breeding lines are proune to produce "bald" children. For example, us in coastal Calif., always wondered about all the fuss about Dusky Challenger. It and that dark line often produces bald and bloom out children. Bald rhizome, bloom outs, and pineappling is very climate induced. A rhizome grown in a colder climate will do fine the first year blooming and increasing. Plant the increase and the following year these increases will be bloom outs. The plus side is that the one bloom stalk is often spectacular being tall, ramrod stiff and large blooms, but that is the end of it.

@GuiseppeJ - I am glad to see that I am not the only one who thinks that Dusky Challenger is overrated.

As Jan and Rob have been using the term, so have I.

There is lot to learn from irises, and even a single term has changed a thought of mine. Thank you for the thread, William.

This thread also gives me an idea...

GuiseppeJ: Thank you so much for the Iris Wisdom. I had wondered in another thread whether I might spare the plant if I fed it a different fertilizer that discouraged bloom, when I saw bloom out happening. But now I see if there is no eye, that would accomplish nothing. The good news is I have lost just 3 to this over multiple years, so I am ok with accepting it for what it is!

Well, I certainly already learned a few things from you all.

GuiseppeJ, like Elsa I really appreciate your insight on the subject.
For me at least, your definition of bloom out, will be the one I will use in the future.

in my limited experience with iris since the 1970's i understood bloom out to be what guissepej described, where every rhizome, single, or in a clump produced a stalk without sending out increases. then the single rhizome or clump just shriveled and died.

i did not experience this phenomena in my garden in northern california, but have since i've moved to socal (in san diego county). (i may have mentioned 7 or 8 have expired this way.). in norcal, i had clay soil , but very rich in nutrients. in socal i have extremely sandy soil, with very little humus.

what i am not sure of is, what might be the contributing factor to the iris demise. i have planted my iris rhizomes very shallow, as i was taught. (bury the roots and half of the depth of the rhizome with half of it showing above the ground. but, some of the irises planted in pots have "sunk" and i've had to pull them up because i had noticed signs of rot starting. )

many of my tb's and ib's live in permanent pots because of ground space issues. for some, it will be their 3 yr. and will definitely have to repot with 2/3 new soil (1/2 cactus mix & 1/2 potting soil) i have 1 of 40 in pots that may experience bloom out after this season, but i won't know for sure until summer. i didn't want to dig it to check for increases this early in the season as it just tried to bloom a few days ago in the rain. i chopped the stem, covered it with more soil, and i am feeding it a dilute solution of 'thrive' (a vitamin b root stimulant). i thought i might experiment on this one potted plant, to see if anything might help?

the bloomouts happened early on with my inexperience of southern california gardening. the rhizomes were were planted directly into that sandy ground soil upon receipt. the iris bloomed their 1st year, and promply suffered bloom out and died.

subsequently, i started planting the newly purchased rhizomes into pots then transfered into the ground, this has helped considerably.

we will have to see what happens to my experiment in the pot?

thank you william and guissepej. william for starting this thread and guissepej for your contribution and explanation.

it may just boil down to mother nature? why some plants thrive and why others die? i'd like to see if my experimentation yields any results?

comments?

Daphne, that's a great post and it is also very interesting that you had less bloom out after you started to plant new rhizomes in pots, before later transplanting into the ground. Sounds like you are onto something there and hopefully it can help someone else in the future.

Do you do something special with the pots in the beginning, like giving them some extra shade or something?

thank you for the acorn william.

the pots are haphazardly placed in the beds where i know they will be hit with the auto-sprinkler 3x a week. for awhile it was 2x then 1 time when we were in extreme drought conditions). however, to this auto sprinkle i hand water when i think the pots in those areas looked dry. not too much shade, my back garden is southwest facing. ( not true west but pretty close)

however i have another permanent pot collection, with about 15+ irises, which i hand water every few days....i check w/a water meter. scattered amongst these larger pots, i also have 10+ one gal. irises, waiting to find a home in the ground or waiting for a larger pot to be transferred. this sits up on a concrete deck and the deck retains heat from the day if the sun is out. not too much shade on this deck either.

moreover, in the front garden, where most of my in-ground collection lives is ne (not true east but...) and is about 10-20 degrees cooler than the back. the irises grow much better in the ground, but do not bloom as much as the ones in the large pots. there's more shade, and i've not experienced much bloom out here, but clumps are decidedly larger than back. (clumps range from about 6-10 rhizomes as opposed to 3-5 )

so, from this limited comparison william, it maybe the warmer the area the more frequent watering necessary. i have tried to deep water, but find this is a wasted resource.

my bloom out occurs mostly in the back, where the sun is relentless in the summer months of july, august, and the first half of september. perhaps, i may just have to water more than i have in the past?

i've noticed with these last prolonged rains (for s.d. county), the irises in general appearance seem a lot happier and healthier. but, have more snail/slug riddled leaves, and no bud sockets?

i may just be overly anxious, but i did see blooms in january through march blooms on many of my rebloomers last year and not so much in 2019. the only ones that did bloom early last year and this were: 'absolute cute', 'capt. thunderbolt', 'concertina' ( re), 'fall empire' (re), and yonkers.

by now i should be seeing more pregnant fans for the april bloom...so far none.

I have had all my increases bloom and the mothers produce no offspring, which is what I, like many here, thought was bloom out. The whole "twist out of the ground" certainly gives an entirely different meaning to your bloom (being) out.

I can't really picture what that AIS definition means. So I must not have experienced it, or recognized the symptoms.

When I first had an SDB which 'bloomed out' one stem & then no increase, I was told to cut that stem & the rhizome did put energy into making so increases & was saved.