I’ve been nursing a purple leafed smoketree (Cotinus coggygria ‘Royal Purple’, below) for a few years, and finally it appears that this is the end. I suspect Verticillium wilt is the problem, and while I’ve pruned limbs as they turn brown, the tree’s demise was inevitable. Though the diagnosis was not tested and confirmed, I suspected wilt, and fortunately, the smoketree is behind shrubby nandinas so the void will not be evident while I decide on another tree that is not susceptible.
The smoketree was planted at forest’s edge, a bit too shaded and not its ideal setting, so the branches leaned towards the path. While the void behind the nandinas will not stand out, the gap to the front will be obvious. I think I have the right filler.
A weeping redbud should work wonderfully in this spot with only late afternoon sun. The space opened by the removal of the smoketree should be ideal for the redbud, and I have my eye on one that is not identified, but must be either ‘Lavender Twist’ or ‘Vanilla Twist’. The identity will be revealed when it flowers in April, but either is a welcome addition to the garden.
Over thirty-three years in the garden, several long established trees and shrubs have been lost, though more to storm damage than disease. The smoketree was quite unruly with its lean, so its loss is an opportunity, and of course I’ve been on a kick the past few years to add redbuds. So, while I’m never thrilled by a loss, I expect I’ll be happier with the redbud.
I also considered an ‘Autumn Moon’ Japanese maple (Acer shirasawanum ‘Autumn Moon’, above). The part shade is ideal and the brightly colored foliage would be perfect with the tall, green nandinas behind. But the redbud is available now, and larger from the start, so the choice was easy, though I’ve itched for an ‘Autumn Moon’ since losing one in overly damp ground several years ago. The similar ‘Golden Full Moon’ maple nearby satisfies this urge just enough to lean towards the redbud, and perhaps I’ll figure some other spot for the ‘Autumn Moon’. That’s usually how it works.
Ramblin' through Dave's Garden 
Verticillium wilt is the most common problem for this species even in our semi-arid climate, but typically in conjunction with regular irrigation. (Otherwise, it enjoys our climate.) Modern cultivars with richer bronzed or bright chartreuse foliage seem to be more susceptible. In our climate, they appreciate occasional irrigation while getting established, but should likely be watered only a few times through summer afterward. The best that I noticed in the Pacific Northwest were on the embankment of Highway 5, between the highway and a rest stop somewhere in the Willamette Valley, in an area that was not likely irrigated.