What beautiful old historics!

Some of the answers will have to come from someone in a colder region than mine, but some things are the same wherever irises grow:

They do need more space between the plants.
The rule of thumb for any perennial is to move them during the month opposite their bloom time.

Assuming these are in bloom now, they'll be happiest if you move them in November...assuming your ground will be workable then.

If you want or need to move them before then, even right now, they'll likely do just fine (iris are amazingly tough), but you might miss next spring's blooms.

Here, I'd say they're planted too deeply & I'd get that gravel off them.

& here iris are so hardy that nobody I know fertilizes;
if the soil is too rich, iris will rot.

Best luck, & I hope you enjoy your irises for many years to come!

Yes to what Sylvia said.

They are too crowded. You should divide them. You can do that about a month after they are done blooming. They usually have grown new rhizomes by then, and you can break them off the mother rhizome that bloomed and plant the new fresh ones. I like to wait until the new babies are good-sized, but you want your plants in the ground for six weeks before the first frost.

They have some leaf spot, that may be from overcrowding. Pull off all spotted leaves and throw them away with the dead leaves when you divide. Cut off any affected parts of the leaves.

When you replant, you can plant the rhizomes about a foot apart so that you don't have to divide them again for a few years. Be sure to leave the top of the rhizome just above the soil surface.

I don't fertilize irises.

Renee

Thanks for the replies, I really appreciate it.

Unfortunately I don't have the option of moving any. This is the only space available. So the best plan seems to be to thin them out. So if I thin them to 1 foot apart it doesn't leave room for many. Could I possibly leave them 6" apart? Which ones should I leave? My instinct is telling me to remove the oldest plants. Should I leave the youngest plants or some that are more middle-aged? The newer ones appear to be planted deeply, but the majority of the rhizomes in the bunch are growing near or above the surface. It's really a tangled mess. Thanks again. Ed.

You can plant them closer together if you wish. The one foot recommendation just means you will not have to divide as soon as if you plant them close together.

When you lift the clump, pull apart all of the plants. The ones that have bloomed can be thrown out in favor of the new fresh plants which will still be attached. Plants that have already bloomed will not bloom again.

Renee

Here is a link that might be useful: How to divide irises

Wow....had no idea that irises only bloom once. Will definitely be doing some digging, separating and replanting soon. Thanks for the link. Ed

hey ed.. where are you in Z5???

here in MI.. after a march hot spell.. that bolted many plants.. we had REPEATED hard frosts. and a couple FREEZES ...

this greatly affected my iris ... and they look not much different from yours ...

they still need to be thinned though ..

these high zone peeps crap me up .. they need to move to the midwest.. [and many who fled such.. need to come back and garden here for a few years] .. lol ...

its not that they are wrong in any sense.. its jsut that they miss the obvious.. ONCE IN A WHILE

and you said: Unfortunately I don't have the option of moving any. ===>> yes you do.. throw them away ... dig the bunch.. keep the best dozen or so.. and throw all the rest away ... give them away .. put them at the curb.. etc .. i will yell ... YOU DO NOT HAVE TO REPLANT EVERY SINGLE ONE ..

ken

ps: you are going to find out.. why rock is not the best mulch.. on a plant that needs to be dug up every few years ... its going to make the job a PITA ...

I'm in upstate NY just north of Syracuse.

Before I do some serious thinning I have a question. If they only bloom once, how can I tell which ones have bloomed? Maybe all the ones in the picture that didn't bloom, have already bloomed. Do next years Irises only come from rhizomes from Irises that bloomed this year? Hopefully I'm making sense here. Just trying to figure out which ones to leave when I thin them. Can leave any smallish healthy fans, or do they have to be babies?

Yes Ken, I believe we had a similar March and April.....messed alot of things up, but these Irises didn't bloom much last year either. They probably should have been dealt with several years ago.

Hi Ed,
Here are some photos to help you figure out which irises have bloomed and which have not.

Dug up irises. The mother rhizome is on the right- you can see the dried up bloom stalk. It has produced one new plant, to the left.

You snap or cut them apart.

Here is a mother rhizome that has bloomed recently, I cut off the bloom stalk, and it has produced two nice big plants already, one to the left and one to the right of the original with the cut stalk. I would throw out the original and plant the two new fans.

these high zone peeps crap me up ..

===>>> OMG!!! ... there is a typo for the ages.. i meant.. CRACK me up.. lol

next to the pool?? how much pool water are they getting??? and what water system are you using.. salt water????

ken

hosenemises, thanks for the nice photos. Unfortunately only a few of mine bloomed this year. Is a recently boomed plant the only source for a new plant, or can I assume that any living fans are potential bloomers? Thanks again.

Ken, that was a great Freudian slip!

Ed, any fan that has not yet bloomed is a good candidate for replanting after dividing, and the bigger they are the better. The fan that has never bloomed may not bloom next year, but it WILL send out new healthy rhizomes and fans that will bloom, at least in my experience out here in the high zones, heh heh!

Renee

You can put an ad on craigslist for the ones you cannot use;
although the mother plants won't bloom again, they'll make babies!

Went and thinned a bunch of them out today. It went pretty well. I think it was fairly easy to tell which ones to separate and replant. I'll wait a few days just to make sure I didn't kill 'em, then do the rest.

Don't worry too much if they lose the outside leaves. That happens.
Renee

Edweather, just wanted to say hi. I live up in Hannibal.

Good advice above. I usually divide my bearded iris in late summer. Simply because it's too hot before then. I think rule of thumb is 6 weeks after bloom. But with our snow cover here, and good old Lake Ontario I divide sometimes right into December.

Hi Polly, I live in Central Square. I might have jumped the gun time wise on dividing them. Just couldn't stand looking at them. I finished the job 2 days ago. The weather is supposed to cool off tomorrow. You are right, it is hot. 95 today! Hopefully they'll be ok. They seem to grow like weeds anyway, and the water table is very high in my backyard, so at least they won't be thirsty.

I doubt you jumped the gun. They will be fine. Nice to have someone in my area on here.

This thread was very informative, and made my iris transplanting job much more efficient and productive! Thanks, all.

Hi, I'm new on here, But I've been growing Iris for over 12 years I have over 18 Colors. I live in Wyoming and was always taught when splitting them to cut the leaves back to 3 inches, and I'm sorry they stop blooming when they are rhizon bound. You just dig them up in the fall cut em back and replant. If in really bad shape it will take up to 2 years to see blooms again, extra plants can always find a new home. I have a waiting list from my beds. BUT they will all rebloom.

What a difference a year makes. This is the same area I originally showed. Have about 6 areas like this one and every place where I thinned them and planted 1 rhizome back, 2-3 are now growing, and some have flower buds. Thanks.

I know this is way after the fact, but the iris that you had pictured is an historic iris by the name of China Maid hybridized by Miliken in 1936. I have several of them as I collect historics. Just thought I would let you know the name.
Happy Gardening