May be a crazy question, BUT, should I be buying from a farm that grows rhizomes in our USDA hardiness zone (or a colder one), or does it really matter? For example, Schreiners is in a zone 8b and I am in zone 6b, will their home grown rhizomes perform well here?

Some would say you should, but my experience has been mixed. I don't know if anyone has done any real research on this, it's mostly anecdotal observations. I seem to have had good luck with Schreiner's irises growing, but have of late reduced my purchases from them due to reduced quality rhizomes and higher prices. (IMHO) I have had good results with Keppel irises, and Mid America irises. I have had mixed results from some of Ghio's and NAPA. They seem to either do great, or not at all. Superstition irises have with a few exceptions, done well for me here. Remember, this is anecdotal observations, not research. I'm sure that others on here will have differing results. It's best to just try some and see how it goes in your environment. There are so many variables to plant growth beyond temperature and climate, that you can't always transfer knowledge from one garden to another, even if it's in the same zone.

with Tom.

So far, I haven't observed any conclusive differences in iris survivability based on hybridiser or vendor and I have irises from Australia, the US, France, Spain, Germany, Italy and the UK. As Tom said, what grows well for you might not grow well for your neighbour.

If we are talking 'bearded' irises Tom and Lilli are spot on. For instance you can buy six from one hybridizer and four flourish for you while the other two struggle to bloom and or survive. It all depends on the genes they inherited from the parent plants. Even sibling irises will perform differently. I think the 'flourishers' are the ones that become historic irises and the ones we have to encourage a lot eventually disappear from most gardens. As for the non bearded types they have different needs than the bearded ones do. As Tom said this is only my opinion and not based on any scientific study.

grannysgarden said:If we are talking 'bearded' irises Tom and Lilli are spot on. For instance you can buy six from one hybridizer and four flourish for you while the other two struggle to bloom and or survive. It all depends on the genes they inherited from the parent plants. Even sibling irises will perform differently. I think the 'flourishers' are the ones that become historic irises and the ones we have to encourage a lot eventually disappear from most gardens. As for the non bearded types they have different needs than the bearded ones do. As Tom said this is only my opinion and not based on any scientific study.

yes, bearded irises.

Orders that I have received from the same source sometimes vary depending on the weather and growing conditions that year, I've had good luck with Keppel, Ghio, and Superstition.

Interesting thought there, Hippie. I've never really thought about that ideal with when I'd purchase plants from a vendor.

The only vendor I've purchased from so far is Winterberry Iris Gardens in Virginia, and everything I ordered seems to be doing fine (in fact, two of the iris varieties tried to rebloom!) but I don't know if in regards, someone from California buys the same irises I did would have the same effects. It's like a snowflake. No two snowflakes will look the same. So, I reckon, no two irises will act the same, whether they're the same plant or not.

UndyingLight said:Interesting thought there, Hippie. I've never really thought about that ideal with when I'd purchase plants from a vendor.

The only vendor I've purchased from so far is Winterberry Iris Gardens in Virginia, and everything I ordered seems to be doing fine (in fact, two of the iris varieties tried to rebloom!) but I don't know if in regards, someone from California buys the same irises I did would have the same effects. It's like a snowflake. No two snowflakes will look the same. So, I reckon, no two irises will act the same, whether they're the same plant or not.

Winterberry is number 1 on my list of iris suppliers.

I have been taking a crash course this year in irises, trying to determine why I lost so many in the last 15 yrs. So I picked up a book on irises from 1965(all I could find at Amazon) that had a lot of important facts about growing irises. Back in the 60's they used 2 different species in the parentage of TB's. One was used mostly in the midwest and required more moisture to do well. The other was used in Cal. and so their offspring do better in dry sunny areas. There has been so much mixing since then that I don't know if it still holds true but I know I never had any problems with iris here in Tx until I bought some from Missouri. I have never even thought about watering Texas grown iris but know now that I may have to when ordering some of the newer irises. Also people don't realize what diseases or pests may be affecting their plants until it is too late. Here I've recently found grubs from June bugs and pocket moles that tear thru roots. Some even have to deal with other diseases such as 'scorch' which may be caused by mites and/or severe weather changes.

I recently talked with Mrs. Horton from Horton Iris and she has to deal with big gophers and uses a systemic for ground insects, as well as a pre-emergent herbicide for weeds, and fertilizer twice a year. I'm sure some small growers have great organic methods for growing iris, but it's just tough to do on larger plots.

So really we don't have much choice if we want some of the newer varieties, we just have to keep an eye on the plants year round, treat them when necessary, keep up the fertility and plan on using extra water when droughts hit. Also it's tough, but we still have to dig them up and replant them every 3-5 yrs or so to keep them blooming.

Maybe some day we'll have a data base for the more vigorous plants for those of us who still just like to plant them and watch them bloom. LOL

Getting back on topic, I just read an article by Don Spoon and he says that there is no real difference in cold hardiness in the recent introductions. I'm assuming the irises released in the last 20 yrs or so. Probably because of so much cross breeding.

IMHO, no matter WHERE the iris is grown, or what conditions it's grown IN, all you have to do is get it through the first year....after that point, the rhizomes that are there are "daughters" grown in YOUR zone . That said.....some varieties do well....everywhere, .....and some varieties don't. There are some very beautiful irises that are known for being "hard to grow",especially in colder areas, but by utilizing "micro climates" in your yard, you usually CAN get them to grow / bloom, even if they never really become "thrivers"

I've found that it really differs from year to year in my own climate and not necessarily where the rhizomes come from. If it is a dry year they perform one way and in a wetter year they perform a different way. I haven't personally seen any trend as far as which irises like my garden and which do not from a specific hybridizer. There are however specific cultivars that I've tried several times and they just won't grow for me.

hippie said:May be a crazy question, BUT, should I be buying from a farm that grows rhizomes in our USDA hardiness zone (or a colder one), or does it really matter? For example, Schreiners is in a zone 8b and I am in zone 6b, will their home grown rhizomes perform well here?

Another idea may be to search up a local iris club to you and/or visit some of their gardens. Local experience with other iris growers near you, would be a good starting point to determine which cultivars are LIKELY to do well in your locale.
And as the others have pointed out, differing locations even in the same garden can have widely different results. As much as I hate to say this, trial and error may need to factor in. Believe me, I've done enough of that over the years. Attending club iris sales is a great way to obtain locally grown rhizomes at an economical price, thus reducing the risk of "trial and error"
best of luck to you.