by opening up the interior.. you will allow more air flow thru the plant .. which might forestall any future mildew issues ...

it looks like you are on the wind blown prairie... it surprises me that you have a mildew issue ... that usually occurs in stagnant night time air ..

unless you wet them every night with sprinklers ..

often.. last years problems disappear on their own .... you may have no further issues with mildew this year ...

btw.. where they new transplants last season??? ... stress does weird things to transplants ...

ken

Thank you Ken-Glad to see your response! Yes, we are on 2.5 acres and pretty open with lots of wind. You are correct, the one that started the problem and spread the mildew was a transplant. The sprinklers dont hit those, but they were all probably under a lot of stress as the summer was extremely dry. I also probably should make sure when I hand water, that I‘m watering the base maybe and not hitting the branches?

If it ever warms up, I will see about opening them up a little more.

Thanks!!

About 10 years ago, I planted some Summer Wine, Center Glow, Amber Jubilee, Dart's Gold and Little Devil ninebarks here in MN. My experience is they always get some mildew, but since the worst seems to hit in June it gets covered up by more growth. Only one year did whole plants get covered in mildew and that was Center Glow and Summer Wine, but they were no worse for the wear the following year. It has not happened since. Last year did seem a bit worse than normal, but it was probably the drought stress. In general, my solution has been to live with it and not fuss too much.

Thank you pennlake! Your experience gives me hope! I was envisioning having to replace them all. i will just have to be patient and hope this summer will be better!