Living in the PNW, Schreiners has more easy access to pumice, though really what size pumice are they talking about?

I searched for horticultural pumice. It looks to be similar in size to aquarium gravel. I actually ordered this stuff https://www.amazon.com/dp/B008YSVPHW/

I am wondering if pots with a special mix would be a better way to handle new rhizomes over winter. I see a lot of rot and it isn't so bad if it is a larger plant, but if it is just a new single rhizome plant there is not that much area to lose to rot. They when they are grown up maybe they will be better able to handle my garden soil? What is a good anti-rot mix?

Lestv said:I must confess that most of my pots have the garden mix I use in the garden for planting. I have lots of that and ran out of potting mix. Since many of my potted iris bloomed, and they didn't suffer rot like those in the garden I feel they are fine in this mix. I do plan on getting them all out of pots soon though!

The pumice says it provides excellent drainage so maybe the Schreiners mix will help prevent rot? That is what I was hoping as well. I had two new ones rotting this spring and it wasn't even a wet one. I have sandy soil which dries out quickly but when it rains here it is usually for a week straight. I don't think the Iris liked that! (It was odd that both the ones that rotted were from the same place, and one was even planted next to the same variety from another vendor and the other is fine. However the same vendor so far has sent me one that wasn't what they were supposed to be. So maybe it wasn't even the same one after all!)

Meredith -- if the ones that rotted were from a PNW grower -- then it's possible that they were very large rhizomes, very fleshy, and found it hard to make the transition to an eastern climate. The exact same cultivar from a mid-western grower, or an eastern grower, could have adapted to your climate more easily. It makes a good case for buying from a grower closer geographically to where you live.

Another option is to hold the plump rhizomes for a few weeks and then plant. It works for me.......I received the advice from a woman name Clare Roberts in an AIS Paper Robin which I participated in........in the 1970's

Hi Paul!

So you're saying to let them dry out a bit? Several weeks -- they'd be dried out pretty good!!! Thanks for the tip!

We get club order from Joe Ghio each year and they are often quite dry but take right off when planted, I held my Keppel order for a while last year and they were fine........

That makes sense Paul. I have never had a problem with a skinny little rhizome but the big plump ones have sometimes given me a problem even a year later.

Muddymitts said:Meredith -- if the ones that rotted were from a PNW grower -- then it's possible that they were very large rhizomes, very fleshy, and found it hard to make the transition to an eastern climate. The exact same cultivar from a mid-western grower, or an eastern grower, could have adapted to your climate more easily. It makes a good case for buying from a grower closer geographically to where you live.

That is great to know! Thank you. Yes the one that did fine was from Mid American which if I recall is in the southeast? The other was from the PNW.

Okay I just looked it up and looks like MId American is in PNW as well.

Paul2032 said:Another option is to hold the plump rhizomes for a few weeks and then plant. It works for me.......I received the advice from a woman name Clare Roberts in an AIS Paper Robin which I participated in........in the 1970's

I will try this next time I get some from PNW. Thanks for the tip!

I must say -- I have never lost a rhizome that came from Mid-America. They grow wonderful rhizomes!!

But I have lost rhizomes from most of the others out there...........

I have not had more rot from PNW irises then any other places including my own state. In fact, some of those larger rhizomes produced large enough increases over winter so that even if the main rhizome didn't bloom some of the secondary ones did. The few that I did loose, no matter where they came from were gladly replaced by the vendors. I have never purposely dried out any large rhizomes either.

We always lay them out on newspaper for about a week. it is helpful for the large rhizomes. Keeping them packed in the box isn't a good idea.

The only thing I've noticed about the 'jumbo sized" west coast, rhizomes, is a tendency to "split". The top of the rhizome gets a split down the middle, over the winter.....which I suspect is do to freezing. I have 'lost" a couple of them....I guess pathogens can enter into the rhizome easier if it's 'damaged'......but, as was pointed out....those biggies have so many increases started, that the loss of "mom" isn't too big a deal.
I know the last several orders from Schreiners were large rhizomes, but definitely not 'wet'....they were VERY dried out, so, somewhere there is a "happy medium", I suppose.