Is my smokebush dying?
We just bought a house this summer with a beautiful purple smokebush in front. We haven't been living in the house and we had an incredibly hot/dry summer so it definitely didn't get much water. The leaves seem fine - there's new growth, but the formerly purple "flowers" have turned a rusty color and are completely brittle (they fall off when I touch them). In addition, the ends of the branches where the flowers are have turned dry and woody and yellow; some break off as well. Is this plant dying? Does it need water? Or is this normal and I just need to deadhead the flowers and wait for fall rain?
King County Washington
Your Smoke Tree (Cotinus coggygria) looks very healthy. It's normal for the flowers to dry out like that--it's what gives it that "smoke" appearance. It's an easy tree to grow. It will do well in any kind of soil, as long as it's very well drained. In our summers, especially this past summer, it's important to give your bush supplemental irrigation-about 10 gallons of water per week, ALL AT ONCE. You want to soak the soil very deeply to promote deep root growth. One way of doing this is to mulch under the tree, and when watering, rake the mulch out into a ring as far as the branches spread. This will create a "swimming pool" that you can pour water into. It will gradually soak in. Then rake the mulch back over the soil again, making sure you keep the mulch at least 8 inches from the base of the tree trunk.
If you want it to bloom, prune back in EARLY SPRING, but only as needed. If you want to shape the tree and make it to a size you prefer, cut back the stems hard to promote the growth of vigorous new stems. OSU has a great publication on how to prune trees. See: http://www.oregon.gov/odf/urbanforests/docs/pruningbasics.pdf