Ccox,
it will do fine in your zone, but everything appreciates a little late afternoon shade. if you have a spot away from the house and septic tank area that receives afternoon shade, plant it there.
Water it really good the hotter it gets.
Take the hose, turn it on to a small amount of water coming out, and drop it at the bottom of the small tree for a couple hours a couple times a week.
Good Luck with it.
I love pussy willow, I would love to have one in my woods.
They are wonderful accents in the house too!

Take the hose, turn it on to a small amount of water coming out, and drop it at the bottom of the small tree for a couple hours a couple times a week.

==>>> generally a good idea for a new transplant.. BUT... it would depend on their soil type and drainage ...

i would suggest you INSERT FINGER... and water deeply [which that suggestions is] .. when the first 2 to 3 inches of soil is dry or hot ... under the mulch ... hot and damp .. usually means dry the next day ...

you water.. when a plant needs water.. NO ONE.. can give you a schedule for your location.. in your soil ... and your ambient weather ...

but again.. the to the above suggestion is DEEP WATERING ... not just a little spray on the leaves ... and that is imperative ...

and mulch PROPERLY.. and deeply.. to moderation day heat on the soil.. and evaporation ... 2 to 4 inches.. depending on the mulch particle size ....

all that said.. once you get it 'established'.. and past the transplant phase ... you will be hard pressed to kill a pussy willow ...

if you have heavy clay soil.. let us know.. we might have tricks for proper planting ... [and if you already planted it.. its not to late to redo it.. if necessary]

ken