[Arid_gardener] Question from Home-Hort WWW page

[jrkwal at cox.net]

Marylee
85710
jrkwal at cox.net

I live in Tucson and planted a butterfly bush in the spring.  It did fine until about 2 months ago and it started to get black edges on the leaves it now has lost almost all of the leaves and it wilts in the afternoon.  It is on the north side of my house but gets full sun.  We have stopped watering every day and have gone to every other day and I have covered it with shade cloth.
I have another bush in a large pot on the east side of my patio it has some black on the leaves but does not wilt and is blooming this it the second season for this plant.
Can any one advise as to how I can help save this bush?
Thanks 
Marylee