Agastache, trouble?

Agastache may be my favorite genus of flowering plants: fragrant leaves, tubular flowers all summer that keep the hummingbirds happy, and pretty much carefree. The only problem I've ever had with Agastache is they sometimes won't make it through our wet winters -- other than that, just ignore them!

Until I got Agastache 'Bolero' this year.

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You see, this plant has a powdery mildew problem!

Did I ever mention that the first specimen I planted died, and that this is the replacement plant? (Still under warranty, thankfully)

Now maybe it's the fact that this is in a new bed, and perhaps the soil is not conditioned properly. Or maybe this area doesn't get quite as much sun as I thought it did (notice that the leaves have lost much of the purple color that made this so attractive in the first place).

Whatever the reason, why can't this plant be more like it's siblings, Agastache rupestris:

or even Agastache foeniculum:

Both of which have never shown any problems, mildew or otherwise.


Anybody else finding 'Bolero' to be a bit finicky? Any idea what the problem could be?

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