My Siberian Iris plants stopped blooming :(

Buffalo, MN(Zone 4a)

About 10 years ago I planted some Siberian iris plants around a whiskey barrel fountain on the north side of my house. The area got some nice afternoon sun and the iris seemed happy and bloomed for me every year until the past 3 years or so when they just stopped blooming.. A nearby tree had started to shade the area a bit more, but that tree came down in a storm last year and I have quite a bit more sun almost everywhere in my yard (including where the iris live) I really love the combination of plants I have in that garden and would like to "revive" my irises, but for the past couple years they have just been clumps of very short (maybe 6" tall) thin leaves=no flowers at all.

I'm thinking that they were unhappy when the large tree was shading them so much -I'm thinking of digging those old clumps out (moving them to another area of my yard) and replacing them with new Siberian Iris plants. Can any of you iris experts tell me why my plants stopped thriving and if it would be OK to plant new ones in the same place?

Thanks so much!
Deb

Cocoa Beach, FL(Zone 10a)

Did you ammend the soil and fertilize each year? I usually fertilize monthly during growing season. The clumps do move upwards so you do have to keep replanting them deeper about every three years. I usually divide at that time.

Buffalo, MN(Zone 4a)

Mine have moved up a bit-maybe an inch or so. Will that affect the bloom? Good point on the fertilizer (guilty!!). They just seemed to always do so well and then they just gave up the ghost. Maybe it's neglect.....What kind of fertilizer do you recommend-10-10-10? I would be so happy if I could nurse them back to health.

South Hamilton, MA

Any fertilizer should be low in nitrogen. Do you divide the clumps? They bloom off the increase & may have no where to go.

Cincinnati (Anderson, OH(Zone 6a)


You might try Holly-tone fertilizer for 'acid loving' plants. Siberians prefer soil that is on the acidic side and so a fert for, say, azaleas or acid other lovers may help balance your soil in that direction and increase your bloom. And/or work in a compost-mulch of pine needles, etc. etc. if you want to go 'natural'.

Pittsford, NY(Zone 6a)

How about Japanese Iris and Hollytone?
Mine look good for leaf color until just a few weeks befor bloom.The leaves turn yellowgreen .I feed them every 3 weeks all season.

Hannibal, NY(Zone 6a)

Sounds to me like they need division. 10 years is about 5-6 years too long to wait to divide. Divide them, and put some fertilizer in the planting hole, 10-10-10 will be fine, but some Holly Tone as Tabasco says will be great. Sibs do well in neutral to acidic soil, so if other plants are growing well, the siberians should do well too.

You'll find when dividing that they grow rhizomes on top of each other as they multiply. You need to get the old dead rhizomes out. It's going to be a job.

Cocoa Beach, FL(Zone 10a)

Hi, Polly! Want to do a road trip to Dana and Sylvia's?

Greensboro, NC(Zone 7a)

I've got a clump on the side of the house that I need to divide...my neighbor gave it to me as a smaller clump and it looked like a nightmare to divide then so I just plopped it in a hole and walked away. Blooming has ground to a halt over the years and this year only one flower has shown. Gotta break out the big shovel and break that mound loose and get to loosening up those poor rhizomes:lol:

Good timing for me to see this post--will amend soil while I've got things tore up.

Hannibal, NY(Zone 6a)

Hi Mittsy,

Jo Ann and I just went today. Didn't this happen last year?

Pittsford, NY(Zone 6a)

dmac065.Get the "sawsall" when you get the clump out of the ground.Siberians have very dense roots,almost impossible to divide by hand.

Greensboro, NC(Zone 7a)

That is good to know--thank you for the head's up! I guess that's why my neighbor gave them to me en mass:lol: Sort of looked like a big football shaped clump of dirt and intertwined roots.

Hannibal, NY(Zone 6a)

Energy drink before, beer later, and you're all set.

Any idea which ones they are? I sure hope it's not one of the Caesars Bro group.

Seriously, don't get discouraged. That's what I do every day spring and fall.

Cocoa Beach, FL(Zone 10a)

I'd love to swap you 25 spring bulbs of narcissus and daffodils for a clump of your no name. siberians. My sister hadn't separated hers for 10 years and as they weren't blooming much, so she no longer wanted them. The bulbs are good sized, most bigger than a quarter. Some of the named ones are Salome, Ice Follies, and King Alfred. Would be happy to add some grape hyacinth and Star of Bethlehem if wanted.

Greensboro, NC(Zone 7a)

Happy to send you some--not sure what they are--let me see if I can find a photo. They are purple and have 12-14 inch flower stalks when in bloom. I've got some coming from a clump sale soon so I suppose I better start making some room:lol:

I'll be in touch with you--most likely won't be messing with them until my next vacation in late June. Love daffs and would be interested in the grape hyacinth--haven't tried those before:)

Couldn't find a photo--sorry about that!

Stamford, CT(Zone 6b)

I'm never sure if mine are Japanese or Siberian, but they have the thicker midrib. 'When the clump in my somewhat shaded garden got to be too dense, we cut pieces out of it. I though my prince threw them away. In any case the following year we had irises by the Japanese maple. I don't remember planting the cut clumps anywhere in that garden, but again we have a ring of irises surrounded by a few that are a bit redder in color.

When the clumps get too tight, they cease to bloom. Give them a bit of space, and there is no stopping them. One thing puzzles me: I never planted that iris in with the Heuchera plants. The Queen Anne's Lace makes a home wherever it wants, but I certainly wasn't expecting to see this bloomin' iris

Thumbnail by cathy166
Hannibal, NY(Zone 6a)

The one pictured is a siberian, Cathy, and they do seed around.

Stamford, CT(Zone 6b)

Thanks, Polly. I always can learn. I also have Ensatas. Are they the only Japanese Irises? They prefer a bit more moisture, and I don't remember if they were bulbs or plants when I put them in about 3 years ago. They are very pretty with rich, deep color..

Thumbnail by cathy166
Hannibal, NY(Zone 6a)

You bet we can, Cathy.

Ensatas are really the only irises referred to as Japanese iris. There is an iris japonica, but it's not hardy for us. It is sometimes also called Japanese iris. And you're right, they're the ones with the thicker midrib. They grow from rhizomes, like bearded irises.

The iris family is so varied and wonderful, isn't it.

Stamford, CT(Zone 6b)

Polly, is it usual for Ensatas to lose their pigments? I have never had white Ensatas, and these are the current blooms. I can tell by one of the new buds that there are still blue/royal purplish blooms to open.

Not only are these white irises bland, but they do not seem nearly as full (or pretty) as those from prior years. We have had very unusual weather since last October.

Thumbnail by cathy166
Hannibal, NY(Zone 6a)

Cathy, I would wonder if that's not a seedling from a seed that dropped off another. Are the buds that look more purple on the same plant? And no, they can lighten up some, but not go totally white.

Cocoa Beach, FL(Zone 10a)

In 10 years a lot can happen! I recently purchased two unnamed siberian seedlings, no known parentage but I fell for them right away. Very different from each other but both special to me.

Thumbnail by mittsy Thumbnail by mittsy
Cocoa Beach, FL(Zone 10a)

pinky lavender, so pretty!

Thumbnail by mittsy Thumbnail by mittsy Thumbnail by mittsy
Stamford, CT(Zone 6b)

Well.... The white Ensatas have dark friends, even though they don't look like the same variety. Somehow, the photos don't look exactly like last year's pix. Petals and falls are a bit different. But there are a few more coming. I don't always remember exactly which plant I photographed.

On the other hand, I was delighted to find this almost black iris starting to open mid-day yesterday. It is the first time this bed has bloomed and probably gets less sun than the other bed. It is probably a year younger than the others as well. It is in a spot that I protect somewhat so that there is no foot or hose traffic annoying it. I know I planted a dark red one here, so I'm hoping....

Thumbnail by cathy166 Thumbnail by cathy166
Hannibal, NY(Zone 6a)

The one on the left is a Japanese (ensata), I don't know the name, and the one on the right is a Louisiana, probably Black Gamecock.

Stamford, CT(Zone 6b)

Thanks Polly. The one on the right is also supposed to be an Ensata, at least it came out of a package labeled Ensata. I've never seen it bloom before, but whatever it is, we are delighted. I googled Louisiana iris, and there is really a resemblance. I've certainly never seen anything like it in my yard.

Hannibal, NY(Zone 6a)

It's definitely Black Gamecock, Cathy. You'll love it. Here it's a slow grower, but you're just a little warmer than we are, so you may need to divide it quite often. I bet you won't have any trouble finding homes for the divisions. :)

Stamford, CT(Zone 6b)

Now that a reasonable amount of time has passed, the purple Ensatas from last year came up exactly as they did before. Therefore I am pretty certain the white and lavender Ensatas must be first time bloomers. Sometimes I feel silly....

The irises on the left are the Ensatas. The dark purple ( if you can see it) has just opened and is gorgeous. The white and lighter purple are the new ones. Guaranteed they were all planted at different times and were purchased separately, possibly from different vendors.

In the second photo, the rich colors are visible on the iris just opening.

Thumbnail by cathy166 Thumbnail by cathy166
Hannibal, NY(Zone 6a)

Don't feel a bit silly. I think your irises are ganging up trying to confuse you, LOL. Very pretty!

Boise, ID(Zone 5b)

I learned something interesting about Siberians this year. They bloom when the soil temperature reaches 60 degrees and will quit blooming when the soil temperature gets above 68 degrees. You can extend the bloom by trying to keep the soil temp below 68 degrees.

Post a Reply to this Thread

You cannot post until you , sign up and subscribe. to post.
BACK TO TOP