If you make a run to Phoenix, we can probably find you a mimosa here at about any nursery, but I don't know what there cold tolerance is. I know the first couple of years, till mine got established, there was frost kill on the top of it. One word of warning, they are very, very, very, very messy trees. Both for their wonderfully fragrant blooms and there leaves when they fall in the fall. So don't plant it somewhere like over your BBQ area, like I did.
Alan
