Yet, they have never turned red in the fall.

Two things come to mind. One is the tree was hit by some sort of herbicide. If the branches are still green/ alive, keeping it watered may save it. Verticillium wilt, a soil borne fungus may be the culprit.

If so the tree is toast and should be cut down. The inner wood of the larger branches may show streaking of green, gray or black. If the leaves look like they are fading/loosing their green color and then falling off, it is probably spider mites. Spider mites are very hard to see - even with a magnifying glass. They like it hot and dry and typically the hottest, sunniest side of the plant will have the problem first.

Mike Larkin. 12 years ago. sounds kinda like verticullium wilt. leaves turn brown dry up and branches turn brown. it acts like a drought. restricts water from reaching the leaves. if you cut one of the branches you can see streaking in the branch if you have it.

The shrubs could keep growing into fall and get damaged by cold weather. Though hardy to ° F (zone 4a), smoke bush may die to the ground or snowline at the colder limits of its range. Elsewhere, leaves and stems might be nicked by frost.

You can also cut the shrub to the ground in fall and mulch it. Jun 27, Smoke tree pruning for a bush is much less laborious. You may allow the extra branches and simply prune limbs to manage shape. The natural splayed nature of growth can be amended by cutting the plant almost to the ground in late winter. This will force new growth and tighten the overall look of the bush.

Sep 09, Look for chewing damage near the bottom of the stem. Just cut those branches back and trim up the rest of the plant to match. Heavy pruning is best done during the winter months. If they had leaves and lost them in the summer, probably spider mites. You can spray for mites. They seldom do a lot of damage to the plant, just knock the leaves off early.