Just a guess here, but locating them in the place you are planning with your climate should help keeping the mildew at bay. I bet it will be fine

John

I have quite a few Diablo here. Full all day sun in clay soil and they do fantastic. Had them in for a couple years now. I've not had it on either Diablo or Center Glow, but did get it on Coppertina so pulled it out this past fall. Wasn't worth having Coppertina with the mess and it was next to one of my Diablo and Diablo still did not get it. Can't say for sure what it will do at your home, but this is my results. One of my very favorite shrubs. Maybe there will be years it does, I don't know but the last two none of mine had a problem.
Cher

Have had 'Diablo' for years in both full sun and part shade and never seen powery mildew on any of it (nor on the Coppertina nor the 'Darts Gold'). My R. banksia lutea gets powdery mildew but I think p.m. is host-specific. My only thought about planting 'Diablo' with W. Wine and Roses is that is a lot of dark foliage all together; you might want a green or chartreuse-leaved plant as one of the pair. I use 'Darts Gold' with dark-leaved shrubs - makes a great contrast. However, now we're in the realm of personal preference!

Here is a link that might be useful: Form and Foliage

The talk of bothersome mildew on these seems to be an east coast thing, it won't remove their concern that we don't have the same difficulty (or level of difficulty) out here.

Note also the cultivar is 'Monlo' and not 'Diablo'.

Here is a link that might be useful: Diabolo® Ninebark (Physocarpus opulifolius 'Monlo' P.P. #11,211)

Oh yeah, I forgot...another one of those Monrovia 'Mon' names...

I also read somewhere

===>>> ya know.. this is right up there with 'un-named sources' ... lol

PM is not an issue of rain .. as much as lack of air movement on warm nights.. when the foliage goes into the dark, dank night already wetted .. these are the conditions that increase PM ... not rain .. or wet soil ..per se ...

i am impressed with your drive.. and your quest for knowledge.. and i encourage it..

but i fear you get to wrapped up in all the 'potential' problems.. that may never happen ...

you said: I just don't want to plant something that I will regret later.

===>>> and i might suggest that you will end up with a selection of the most boring plants known to gardeners.. on the simple fact that you fear every 'possibility' of what might happen ...

ID something you cannot live without.. and makes your toes curl.. and plant it ... and IF... key word 'IF" problems happen .. then deal with it then ..

but dont end up with a bunch of boring plants.. that are bullet proof to every know 'possible' problem ...

also.. in my world.. i go small.. so it costs substantailly less money for the plant.. so that if i ever have to cross the road of removal ... it doesnt hurt as bad ... in other words.. i will pay $20 and kill it in 5 years.. if it bugs me... rather than spend $250 for a large specimen.. and then never have the ability to kill it.. due to the excessive investment ... [and i could have 12 plants for the same $250 investment.. and if two become problems.. i am still 10 plants ahead ... i have spread the risk over more plants] ... and that is a long story to say that instant gratification might be why you fear failure ...

good luck on your quest ... i am impressed with your research ...

ken

I was raised in a rural area not far from Fargo, the horticultural Utopia also referred to as the end of no where.

In those regions, ninebark never suffered the lack of attention that it went through in other parts of the country, so when the purple leaved varieties came out, we generally looked at each other and shrugged, cuz ninebark is never anything to get too excited over. Dirr said it best in one of his infamous quips, just about anything is better.

The good news about ninebark is that it's hard to kill. It will grow anywhere with a maximum amount of neglect, even moderate amounts of abuse. It will survive in shade, even though it won't really be happy (or color well). It will survive drought and desiccating winds, and shrug off winters on the plains of North Dakota and ask if that's all you got. My grandfather once put one through a combine; we replanted it and it survived.

If it ever gets overgrown (which it will), you can cut it back. When branches die apparently without reason (which will happen), cut it back/out and the plant will thank you. To keep the best color, a hard pruning is recommended (best color on newer growth), which will keep some of the other problems from developing.

Don't research things too much...you'll find a reason not to do it. Some information is good, and sometimes more isn't so much better, rather, just more.

>Dirr said it best in one of his infamous quips, just about anything is betterSnort! 'Monlo' has more than made a place for itself in gardens with its purplish leaves and the reddish fruits are striking before they mature to brown later in the season.

Plantingman - The latest issue of American Nurseryman has a comprehensive article about powdery mildew and Physocarpus - results of a study conducted at the University of CT. I'm attaching the link.
Sara

Here is a link that might be useful: American Nurseryman Feb 2012

Thanks for the article. Very interesting reading. Also interesting about the new dwarfs they are coming out with this year.
Cher