Ask Mr. Smarty Plants

This USDA Plant Profile Map does not show Cotinus obovatus (American smoke tree) growing natively anywhere close to Washington State. The Plant Profile Map for Psorothamnus spinosus (Smoketree) shows it native only to California, Nevada and Arizona. There are 3 other plants in our Native Plant Database with the word "smoke" in their common names but none are what we would call trees.

The Lady Bird Johnson Wildflower Center, home of Mr. Smarty Plants, recommends the growth, propagation and protection of plants native not only to North America but also to the area in which those are being grown; in your case, Clark County, WA on the southwestern corner of Washington State. This is to try to ensure that the soils, rainfall and climate are right for the plant in question.

According to Missouri Botanical Garden, there is also a Cotinus coggygria, in the same genus as Cotinus obovatus (American smoke tree), but native in southern Europe to central China, which means it would not be in our Native Plant Database.

However, although we obviously cannot say if your plant will do well in your location, we can tell you that our recommendation for the planting of woody plants (shrubs and trees) is that it be done in a cool time of the year; probably October or November in your area.