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fearlessem

help with diagnosis?

fearlessem
13 years ago

Hi folks --

I'm new to iris growing (planted them two or three summers ago for the first time)... Last year I actually had lots of beautiful blooms, but this year, something's going on. I've read up on iris problems, but I'm still confused. Don't think this is rot, as I don't have any smell or rotting leaves... I dug up one plant and didn't find any borers (but maybe its to early to see them?), though there was what looked like a hole and a rotten part that must have happened last year... Yet the clumps are barely blooming, many of the stalks I have are stunted, some of the leaves are yellowing, and the fans are leaning over rather than standing straight up. I've attached two photos...

Any thoughts on what's going on? I did make the mistake of mulching last winter, which I now know is a mistake... Could that be the issue?

Many thanks in advance for your help...

Emily

Comments (6)

  • iris_gal
    13 years ago

    When healthy strong rhizomes are sent they have hidden buds inside. So bloom occurs nicely. If they are not a vigorous variety it may take 2 years for more flower buds to form.

    Typical for them to look this way during summer.

  • Nancy
    13 years ago

    I agree with iris gal. Are they still in mulch? I leave just a bit of the rhizome above the soil. If there is a bit of mulch on top, I'd try to pull it off. A lot of mine are getting the brown spots, they will look much worse by July. Seeing holes doesn't necessarily mean borers, the large roots of the iris can naturally die off & leave the holes.

  • jsky
    13 years ago

    If this is only one year's growth or two, it's very prolific. Will need alot of thinning out. I usually plant mine 20-24" apart. That gives them plenty of space to multiply. Also once the rhizome has produced a stalk, that rhizome won't produce another one. So it's DONE!
    Also did you fertilize and if so how heavily. Irises don't particularly like alot of attention.
    Good luck!

  • hosenemesis
    13 years ago

    They may need to be divided again already. They stop blooming when they get too crowded.
    Renee

  • fearlessem
    Original Author
    13 years ago

    Thank you all for your replies... I thought about dividing them as Renee suggested, but I feel like I've seen many people around here with clumps that look far denser, and theirs are blooming like mad! But is the consensus that these look too crowded? I certainly didn't plant them two feet apart when I started them two years ago -- probably more like max 16 inches apart, as I wanted them to fill in the space quickly...

    The mulch that's left on them is very thin now, though I could certainly get rid of all of it. I can check about the planting depth, but it seems as though if they bloomed well last year, it would be strange for them to suddenly be too deep now...

    Irisgal -- I think these are supposed to be fairly vigorous reblooming varieties... Your thought is that this was typical for second-summer growth -- is the fact that all the fans are slanted that way normal too?

    Again, many many thanks for the help...

    Emily

  • iris_gal
    13 years ago

    I thought maybe something had sat in the middle of the clump. Mine grow in ammeded adobe. Mostly straight but as the clump enlarges some tilt a bit and during summer the fans lean without their firmness of spring.

    You're in zone 5 and not many rebloomers will repeat their show in the colder zones. They benefit from regular deep irrigation during summer and another application of fertilizer after bloom to perform again. Low nitrogen fertilizer!

    It's possible for soil to be too wet. This causes shallow weak root systems. After you remove the mulch and allow the tops of the rhizomes to sunbathe, check soil moisture with your trowel. The top 5 or 6 inches should be dry before another soak.

    The most important soil issue for beardeds is drainage.

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