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alisande_gw

Does hardiness vary from iris to iris?

alisande
17 years ago

Last year I ordered a bunch of irises without thinking about individual hardiness, assuming they'd all grow in my garden since irises are seen everywhere around here. They all grew beautifully and many are blooming...but it was an unusually mild winter.

This morning I sent off another order, again not considering hardiness. Was this a mistake? Are some bearded irises unable to tolerate northern winters?

Thanks!

Susan

Comments (15)

  • laurief_gw
    17 years ago

    In my experience, irises vary considerably in terms of winter hardiness, resistance to disease, vigor, and bloom performance. I grow a couple of hundred TB cultivars, but I've lost more than twice that many over the years. On the flip side, most MDBS and median beardeds do wonderfully here. It's primarily the TBs that are problematic in my climate and growing conditions. It's taken about a decade to develop a decent sized collection of TBs that are tough enough to handle northern MN.

    Laurie

  • wmoores
    17 years ago

    Conversely, a lot of irises developed in other climates (not necessarily cold) will not grow and bloom well in the South; others die out right.

    I have no problems with Francis Rogers' irises (Wisconsin) or Jack Worel's (Minnesota), but I have trouble with a lot developed in Oregon. Parentages and in-breeding are things I look for when I buy an iris. Often, though, Schreiners and Cooley's do not reveal the parentages until after an iris has been introduced. I like catalogs that give the parentages and other information about all of their introductions, so you don't have to wonder about the parents. Even with all of this information, the iris still may not perform in your climate.

    The above refers to introductions. If something has been out for a few years, you can ask folks on the Forum or in your local iris club what grows for them. Join the AIS and get the regional newsletter that has the symposium in it. That will tell you if an iris grows in your area or not.

    The online iris register does not list parentages until two years after an iris has been on the market, so unless you buy the paperback Registations and Introductions book, you cannot find out. You still have to wait a year to get parentages for Schreiner and Cooley irises.

    There used to be an iris hybridizer in the San Diego area of CA. Most of those irises were not cold hardy and those genes are still in the ancestry of many modern irises.

    If you are in an 'iffy' or 'vale of tears' climate zone, I would also avoid irises marked with the bloom season of VE, E or EM. This can help in getting the right plants but isn't always accurate. If you have no late frosts or freezes, then they are ok.

    Walter Moores

  • njiris
    17 years ago

    I never see an iris catalog state that an iris is suited or not suited to a particular climate. Its always tells you how vigorous the cultivar is. Period. Years ago the cypriana, riccardi or mid eastern 'blood' in early tetraploids would signal a 'tender' tag by the commercial iris growers, but not any more.
    The best results come from iris that have been developed in a climate like yours. Look for a commercial iris grower close to your area, and look for his lowest price iris. Those are the ones that have proliferated abundantly for him and will probably grow well for you too.
    Laetitia

  • alisande
    Original Author
    17 years ago

    Thanks, all. Your iris knowledge far exceeds mine.

    I've been ordering from Blue J. Nebraska sounds like a climate similar to mine, but actually I have no idea if that's true. The ones I order are not expensive, though ($2.20 apiece). I've never heard of iris breeders in my area. There are probably some in the southern part of the state, but that's two or three zones warmer.

    For right now, at least, I'm very much enjoying the show in my garden.

    Susan

  • gmason
    17 years ago

    Don't conclude that every iris that died in its first year is not hardy in your area. This year I lost Conjuration. Went from a fairly large clump to nothing. I know Conjuration will thrive in my area. Some plants take a year or so to settle in. Sometimes I have gotten a replacement iris and had it thrive.

  • mad_gallica (z5 Eastern NY)
    17 years ago

    Something to keep in mind is that with iris, cold hardiness isn't the only criteria, or even the biggest criteria. Moisture resistance is also important. An iris can be perfectly fine as far as cold temperatures go, and completely unable to handle anything over a certain amount of rain.

    In general, the further west you go in North America, the drier it gets. I wouldn't begin to trust anything west of the Mississippi regarding eastern rot resistance. It doesn't automatically mean it can't grow here, but it also doesn't automatically mean it can. Iris from climates that get rain during the summer are much more reliable here.

  • njiris
    17 years ago

    When you order a bunch from a place like BlueJ, some will do well, some wont;you will be surprised at how well some do even if they come from a faraway place. Since BlueJ's prices are reasonable and they are generous with bonus, losing a 2.20 iris is not as painful as losing a Schreiner's 25.00 rhizome of equal beauty. Its a learning experience, and you will soon see which ones like your garden the best. Its not always a question of climate. there is soil, moisture and who knows what else, that determine if the iris will thrive. I am always astounded that some iris do well for me and the same iris do not do well at Presby, 20 miles away, and vice versa.
    Trial and error work best.
    Laetitia
    Laetiita

  • Springshowers
    17 years ago

    If you really like an iris that dies out the first year, I'd suggest trying it again and plant it in a different location. I've tried Batik for 5 years (you'd think I'd give up, hu?) and every year it winter/spring rots on me. However, last year I got 2 healthy rhyzomes from a gal in a trade and low and behold one of them took off and is actually blooming and looking great this year! The other rhyzome looks fine but without all the increases and no blooms. I've also had iris that were planted with all the others (that grow great) and they didn't do much (bloomed close to the ground, not many increases, etc). One of them was Covet Me. Last year I'd had enough babying this one and gave them all away except one that I threw in the ground on the west side of our secret fence. It started increasing like madd and this year has nice tall stalks with lots of blooms. So for me, I've learned that sometimes persistence pays off if you're willing to try new sources and plant in different places.
    heidi

  • rebel44
    17 years ago

    I have had iris just hang on for two years and never bloom and then move them about 500 feet to a different micro climate and they take off. I like to think I can grow just about any bearded iris if I just find the right spot. Lee Mincy

  • wmoores
    17 years ago

    My conclusions about certain irises not thriving in a given area was not based on just one season.

    I have tried Happenstance so many times I cannot count. It seems to adjust after fall planting but does not survive the winter. At least five attempts at growing Feature Attraction and Sea Power have ended in failure. None was ever planted in the same spot where a previously planted one had died, but I did plant a different iris in those spots with no problems.

    Sometimes if somebody close by gets a difficult iris to adjust, it may help it adjust to your garden. I don't know of anyone in the immediate area who has gotten the above to survive.

    Queen of Hearts and Edith Wolford got the most complaints on the old iris-l chatline about not surviving or performing.

    Walter Moores

  • gmason
    17 years ago

    Wow, Sea Power and Happenstance huh. I have had both since they were new and thought they were the models of hardiness. But then I have heard occasional rumblings about Schreiner blues not prospering in the southeast. They all have been super hardy for me.
    As for the old east coast/west coast thing,I think anyone who went to the convention probably noticed that some of the holes in the planting beds were east coast iris. They probably also noticed that we are not strangers to rot. I grew up in Idaho and even then learned that the Achilles heal of tubers and rhizomes is rot. It just comes with the territory. I totally agree with the moving them around notion. On the other hand, if I lived in the southeast and found that Walter couldn't make it survive, I wouldn't try it.

  • wmoores
    17 years ago

    Keith Keppel couldn't believe the story I told him on Happenstance. The last time he sent me what amounted to be an entire clump. It did not make it.

    The best pinks for the South come from Vern Wood in CA. They grow like kudzu.

    Sea Power is out of two Schreiner blues, so that should have been a red flag for Sea Power, but hope springs eternal. Keppel's irises did much better for me when he lived and hybridized in CA.

    Schreiner blue amoenas/bitones are particularly notorious for disliking the south. Best Bet took a while to adjust but finally did.

    I had a gigantic clump of Yaquina Blue, but it never bloomed, so I tossed it several years ago.

    For me, the older Breakers has been Schreiner's best blue.

    I wonder why there is no hype on Schreiner's Pixie Dust. That is the best iris that has bloomed here in many years!

    Over all, I would say CA hybridized irises do the best for me.


    Walter Moores

  • rebel44
    17 years ago

    Walter, I may give Happenstance a try. Even though we are fairly close together with about the same climate I believe your soil is much richer than mine and probably entirely different as far as organic content. I have one area that I move iris to when they are not happy and so far all have become happy quickly, usually blooming the next season. Lee Mincy

  • mosaic_wench
    17 years ago

    Funny how some cultivars do better than others around the country. My Best Bet started as one nice rhizome from Shreiners and is now multiple large clumps around my zone 5 yard.

    Dorothy Lee thrived and grew for 5 years before she bloomed - and what lovely bloom season she had - 27 blooms over 2 weeks. But I might have tossed her on the compost if this year wasn't the year she bloomed. I was sick of waiting!

  • etbaldwinpfp
    8 years ago


    Am impressed with the experienced iris growers here. I grow many things but am now considering iris for a windy zone 4 are (Bend, OR, area). There is irrigation to this site.

    I have some very robust The Vicar (Schriener's) which have increased well and was considering transplanting some from a zone 7 to this zone 4/5.

    Anyone have experience with The Vicar in this colder zone? Any successes with other varieties? Looking forward to hearing from your experienced iris folks.


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