What do I do with the iris after they have bloomed?

Silver Spring, MD(Zone 6b)

For the life of me, I can't remember if we cut the spent bloom off after it has finished blooming or do you cut the entire stalk down or let it die back like daffs and tulips?

South Hamilton, MA

Cut the stalk to avoid rot. Keep the leaves growing.

south central, WI(Zone 5a)

Also might want to check for the dreaded iris borer. Just in case, when done blooming ideal time to look. Wished my former neighbor had done it...wish I had known about it>

South Hamilton, MA

Look at the leaves. If there is a 'gooey' sticky substance along the border of the leaf, than feel for the borer. It can be squashed before getting to the rhizome. Fewer borers are present if irises are away from shrubs.

Dover, PA(Zone 6b)

Pippi hope you don't mind my adding a ? to your thread.
Is this borer damage or some other pest and can anything be done to stop this? Not all but quite a few of my Iris are doing this. Starts with a few spots on the leaves and then they just get worst and worst.

Thumbnail by HollyAnnS
South Hamilton, MA

It looks like leaf spot.

Dover, PA(Zone 6b)

Thank you that is what it is. The bed that I am finding it in wasn't well cleaned or weeded this year. Only just recently got around to weeding and cleaning it up.

Hanceville, AL(Zone 7a)

Is it true that an iris rhizome that has bloomed once will never bloom again? I was told this a few years ago and never have had any confirmation. Can anyone confirm? Luciee {;^)

South Hamilton, MA

yes irises bloom on their increase.

Hanceville, AL(Zone 7a)

Increase being the new rhizomes? And how long does it take for blooms from these rhizomes? I have been a dabbler in irises through the years and have heard many things, but now I am old, I want to know if things are true. Luciee {;^)

South Hamilton, MA

It depends on the cultivar. Dwarf irises are quicker at putting up new bloomstalks the following year, but all irises differ in rate of growth. they can be helped along by compost or fertilizer. The plants do need something to eat. ☺

Hanceville, AL(Zone 7a)


Thanks, irisMA. Luciee {;^)

Trumbull, CT(Zone 7a)

If I may ask, does it help to leave the bloomed rhizome in place with leaves to sort of feed the daughters or should it be cut/divided out at some point? I read that you said to just cut the stalk but if the clump gets too large can you cut out the mother in place with minimal disturbance of the daughters?

Our Iris garden that has not been maintained in about 8 years has about 6 clumps with a total of about 20 to 30 plants and we get about 3 blooming stalks every year. If I divide and clean it up I want to do it in such a way that maximizes blooming. Feeding them will help of course and I now understand that disturbing the soil and roots will set them back but I've left some undisturbed so there might be hope.

South Hamilton, MA

Certainly you can lift the entire plant about 6 weeks after bloom. I sounds like redoing the entire bed with compost & resetting the divided plants would be good for your situation.

Knollwood, TX

So, irisMA, if I have rhizomes that obviously had a bloom on them last bloom season, they will NOT bloom again? Should they be gotten rid of, or will they grow more rhizome & a new shoot? If that's the case, won't you end up with a really long rhizome with lots of already-bloomed sections? Sorry for the confusion on my part... really new to this. :)

South Hamilton, MA

The rhizome which bloomed will not do so again. The new increases with leaves will produce next year's bloomstalks. After about 3 years the plants should be divided & reset. Cut the present stalk after bloom has finished.

Cherryvale, KS

Elsieme, the old rz will often send out new rz, if it is firm and healthy. pic Heaven's Edge

Thumbnail by NickysIris
Enterprise, AL(Zone 8b)

I am new to Iris growing and the part about the new growth of the rhizomes completely baffled me, and still does. I was just given some very nice Iris so I am told, and just yesterday I planted them. I added sand and compost to the soil, and I planted them on a sloping part of the yard that drains very well and gets at least a half day of sun. Of course with all the rain we have had, I think even total sand would be taxed to drain all the water away. I guess I have just always assumed that once the Iris was established it bloomed every year, then every three or four years you should dig them up and then it might be a year, possibly two, before they bloomed again. But if I am understanding what is being said, the Iris might bloom one year, then take a year to grow a new rhizome and then bloom on that new growth the next year. Is that correct, Iris don't bloom every year?

Lyndon, IL(Zone 5a)

You should expect bloom every year. It may take a year for them to "get going", but from that point on, there are new "increases", in all stages of development, coming along to maintain bloom. Generally, after 3 to 5 years ,or so, crowding of the clump will start to reduce the amount of bloom. Then it's time to dig, divide, and refurbish the soil. If you do this in late June, to early August, there's generally enough time for them to settle in with some new growth, which will be the next year's bloom. There's tons of on-line articles on digging ,dividing, etc. You will find that some cultivars need separating more often than others, and some ,in fact, are so hardy that they will literally take care of themselves( generally older, so called "historics). Read a few articles, grow them a while, ...you'll get the hang of it !....Arlyn

Enterprise, AL(Zone 8b)

crowrita1, Thank you very much for that response. I have read several articles and for some reason it was just never clear to me. Your answer is the very best explanation I have seen, I now understand. I will expect these darned Iris to bloom every year after they get established! Thanks again.

Dallas, TX

I'd like to add my experience with irises. In Austin I lived in a house built in the late 1920s. The owner (who was the only owner before me) had planted approx. 12 separate iris beds in the back and front yards. Most bloomed sequentially as the sun changed its path. Each bed was composed of a different type of iris. When we broke out of our inertia, we did some cleaning and a little dividing, usually in the fall. Never did much else and always had blooms galore.

Here in Dallas I recently 'liberated' some old, neglected irises from the alley behind my late neighbor's garage. Gave some to other neighbors who planted them immediately (this was in the spring) and they had blooms right away. The rhizomes that I planted (much later) are starting to sprout new leaves so I'll be looking forward to see the spring blooms. I'm also looking forward to finding out what color(s) they are.

Last week I went over to 'liberate' a few more rhizomes and saw that there were many new ones growing from where I had thinned them.

Sorry I can't add pictures of the rhizomes. I think it would be really helpful for y'all to see what I'm talking about. Terminology can get confusing, at least to me. But alas, I have no camera or smart phone so pictures aren't possible.

I'm a firm believer in 'benign neglect' when it comes to irises. Good luck with yours!

Enterprise, AL(Zone 8b)

Posting a picture of some Iris, any suggestions on why the leaves look so bad?

Thumbnail by Seedfork Thumbnail by Seedfork Thumbnail by Seedfork
Concord, NC

here in the Southeast and especially with all the rain this year iris are more prone to leaf spot and also bacterial soft rot and crown rot. to much leaf spot spread here in the southeast's humidity can weaken the plants immune system as can cutting them into fans here as it opens up the vascular system of the plant to disease. I can not tell but in the first two pics are some of the ones leaves flopped over?. if they are see if the rhizome is mushy and leaves mushed and eaten off at base and has a vile smell. that is bacterial crown rot or soft rot. if it has not yet devoured more than half of the rhizome you can take a metal spoon and remove the mushy part completely and soak whats left of the hard rhizome in 1 cup of bleach in 10 cups of water, or, if you only have a couple rhizomes to soak 1/2 cup beach in 5 cups water. soak for 20-30 minutes and rinse off under tap water for a few seconds and replant in clean potting soil. if the old dirt you pulled it from has any of that slimey puss or slimey roots left it can recontaminate the iris again.
Also the best thing for leaf spot here in the southeast is keep the iris tidy by removing completely dead leaves and debris in summer months and worst leaves more than 75% covered with spots at base of rhizome and throwing it out in trash-can or burning it. do not put them on your mulch pile!. then in winter in December remove all the dead leaves and throw them out as well before the new Spring growth.

Dallas, TX

Seedfork, I don't know why you think your irises look so bad. That's just kinda the way they look after they bloom. I don't know about leaf spot as to whether it does any damage. I'm not sure that I agree that leaves that are flopped over are a sign of rot, but I will defer to Mikesmom.

Yesterday, I went to one of my favorite nurseries and they were selling irises that are 're-bloomers'. Of course I couldn't resist. Never heard of any such critter before. Apparently they bloom in spring, as usual, and then again in summer or fall. They say that the 2nd blooming is not as showy as the spring display but last into the fall.

The nursery gave me a 2 page handout but I don't know if there's a link to it or if there's a copyright. I hope to go back this evening for their monthly happy hour plus what they call a 'pop up' class on irises. I will ask if I can share the handout or if there's a link to it. Or I'll look for a link right now. If not there, I'll call and see if I can at least share the major points. Like it's a common mistake to plant irises too deeply. And that over watering is a big mistake. Or that, with some exceptions, irises do best with at least a half-day (6-8 hours) of sun.

Back at y'all later.

Lyndon, IL(Zone 5a)

I sort od agree wit flower child. My old eyes aren't seeing the pics very well, but it looks like you've got what I call "brown tips", I seem to get that in very hot conditions, on iris that are in full sun, and those with afternoon shade don't seem bothered by it. You may have a little leafspot, and as mikesmom says, the best thing you can do is a real good clean-up at season's end, although you CAN spray a fungicide, which will help a lot. The leaves laying on the ground is usually a natural thing. When the leaf is "spent", it will get very yellowish in color, turning to almost brown. If you give a gentle tug on the leaf, it'll come off very easy, and then dispose of them in the garbage, as mikesmom said. If you DO have rot, the base of the "fan" will be soft, and gooey, with a terrible smell. If so ,treat for it as mikesmom said. If you can post some "closer" pics, that would help. If you want more info on iris diseases, and care, just google "iris diseases", and you'll probably get a zillion hits. Pick one of the university ag websites, they usually have pages for iris, and you can pick one that's close to the same climate you have. ...Arlyn

Dallas, TX

Short answer. Website is nhg.com. Can see them on Facebook: Northaven Gardens. Don't say much about the re-bloomers except to show some pics and say that they are selling out fast. I can attest to that as I wanted the Mariposa and it was already sold out yesterday. Large variety, many colors, various heights. I would think that if you are serious about buying, you could call or email or FB them. And no, I am NOT affiliated in anyway with this garden center. Just like them. Gotta get ready for happy hour and hope to have more info later.

For what it's worth, I personally would not attempt to save any irises with crown or root rot. They really are vile. And I don't know if there is any way to save rhizomes that have borers. Not as vile as rot, but oh ick.

Concord, NC

spray fungacides that are available to the public in retail quantaties are pretty weak like daconil and propaconizol and would only barely make a dent on leaf spot if applied with the first start of early new baby growth in the Spring when the leaves start coming up as a deterant. to truely make a dent and stop the spread of leaf spot in the hot summer months on a large colony of irises say in a large bed you would have to use something commercial and nasty thats toxic like Mancazeb or Copper sulfide a heavy metal, which are both extremely toxic to animals and birds and even remains in human cells and the water table. I would much prefer abit of leafspot to dead animals. they best way to prevent soft rot issues is the use of bonemeal in the Spring and then again in the lmid to late Fall. the calcium makes the irises hard and more blight resistant. and again the most animal and enviroment friendly and tried and tested old fashioned way of taming leaf spot is complete removal of the old dead leaves in winter months and keeping the garden tidy year round by even removing leaves with the most disease in summer months by hand at base of rhizome.

Dallas, TX

so, does leafspot actually do any damage to the plant?

Lyndon, IL(Zone 5a)

Yes. Any thing that reduces leaf area, reduces the plant's ability to produce food. leaf spot left un-treated, for the long term, can weaken the plant to the point it will die (usually it gets weak, and then soft rot finishes it off, at least in my climate). Clean your beds, dispose of the "trash", and , if you desire to, begin a spray program with fungicide. Keep your beds "open"(allow some room between the plants, for better air-flow, and sunlight penetration). Don't work in the beds when the plants are wet. Get some info on the web from your local university, and your local AIS webpage. Your county extension office probably has some info, or, at least links to it's Master gardener program( seems like every county ,in almost every state has them). Find out what works for others in your area, as every locality has some differences in climate....Arlyn

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