Thank you! A lot of good information in there, thanks for writing it!

Question: I collected swelled seed pods from an isolated stand of identical iris, but the pods were all empty. Do you think that the pods formed because self pollination did occur, but there was a self pollination inhibitor at work that stopped seed from forming? There were only a few pods of varying sizes in the stand of maybe 200 iris stems.

Also when I collected a few stray rhizomes from the same stand, I found many of them had smooth tunnels bisecting the rhizomes. Is this because an attached rhizome had rotted and fallen away or due to insect damage? Due to erosion on a slope, the rhizomes collected were actually a fraction of an inch above soil level, connected only by roots and rhizomes to the side. They still had stems, leaves and starts for next year on them, despite the damage. Do you think they might also harbor insect pests?

I'm not experienced with empty pods in iris, however, with daylily it usually means that there is a mismatch in ploidy. Sometimes a pod will set when a diploid pollen us used on a tetraploid flower or visa versa but the mismatched ploidy will abort any seeds that begin to form. Usually the whole pod falls off but they can sometimes develop as "airpods". Self pollination inhibitors in my experience either completely fail to set pod or the whole pod aborts much like a ploidy mismatch. I've never heard of anyone having a self pollination air pod though that doesn't mean it can't happen.

Another factor is if there is not sufficient water to maintain the seed development.

Tunnels in iris rhizomes, especially if it was fresh rhizome tissue, sounds like it could be iris borers. I don't have any experience with those but have heard they can devastate a garden. Hopefully someone on this forum knows how to deal with them. I've been advised to check all new rhizomes before planting them in the garden, cut out any suspected infestations, remove all dead foliage and soak the plant in either an insecticide or bleach water before planting.

Maybe it was iris borers. I'll watch for leaf damage next spring, in case any eggs came along with the rhizomes, though I cleaned off the dead aerial parts. I didn't know about the bleach water before, and it's too late now, the snow is coming down out there right now!

Found a good page on iris borer with clear photos

Here is a link that might be useful: Iris borer photos

I got an error message that the site couldn't be found.

wmoores, you have e:mail. I sent it to you directly. The site works OK for me even w/o signing in so not sure what the problem was for you???