I don't grow Lousiana Iris so don't know if they can be saved.

When you see bearded iris damaged by iris borer you should dig them up and trim away damaged leaves and/or rhizome parts (and squish any borers you find!). They say not to compost that cut away stuff so as not to continue the spread of borers.

Anyway, what's still ok can be replanted. They recommend cleaning them before replanting with a 5% or 10% solution of clorox and water, but I don't bother with that.

They'll survive. Even if you don't dig them up! You'll detect the occasional rotted rhizome if left, but otherwise the damage is done.

The way borers work is: they're little white moths in summer... they lay their eggs in the debris around iris in late summer/autumn and the eggs overwinter there. In spring they hatch and the tiny larvae climb the leaves, make a pinpoint hole, and burrow inside. They spend the spring and early summer eating their way down through the leave, enter the rhizome, then pupate. They are large white/pink larvae inside the rhizome -- sort of pretty, really. :) Then they hatch into small white moths -- around August here. Then the process starts again. :)

The best prevention is to clean the debris from around your iris in autumn. It cleans up their eggs and leaves them with no protection for the winter.

I had them last year for the first time in many years. blech. :(

Thanks party music, If your method works for bearded iris then it should work for La. Iris also. I have them all dug up and the rhizomes cut off that were damaged. Can I replant them in the same area they were in or do they need to go in a new bed. I don't know if I have the strength to dig a new bed after digging all these up.

Penny

Penny,
I don't have any advice for you, but I'm sorry to hear about the borers :-(
I hope you get rid of all of them without losing all your tubers.

Linda

They recommend a new planting area -- but it's not necessary. Chances are good that you've found and dispatched all the large larvae at the point where you've seen the damage and done the digging. Just sift through the soil before replanting to find and kill any stray larvae.

Thanks Linda,
I hope I don't lose too many either. It took me a while to get thise and they bloomed for the first time last year. This year I would have had a beautiful display if it hadn't been for the borers .

Party musis
U gad read about planting them in a new bed which would have been difficult as I would have had to dig up another section of lawn and amending the soil. At this late date it wan't something I was looking forward to. I will be able to sift through the bed and hopefully get them replanted this week end.

Penny