In our efforts to restore the urban forests and other habitats of Seattle, we use native plants to enhance the ecosystem functions and biodiversity of species in our open spaces. However, what is meant by "native plant" can sometimes be a matter of informed opinion. So what is it that is usually meant by native plants and why might Silk Tassel Bush be on the list of some restorationists and not on others?

Restoration workers like to use only species historically found in that area, prior to European settlement. It is easy to see that Douglas-fir, Big Leaf Maple, and Sword Fern were all found here before George Vancouver and Lewis and Clark. It is harder to determine that for a plant like the Silk Tassel Bush. What happens when you reach the edge of an area, the limit of the range of a plant?

A plant's home, or native range, is determined by a host of influences such as climate, geology, soils, hydrology, biological interactions, and natural dispersal. Living things disperse within their native ranges by moving around on their own or with the help of air, water, wind, and other animals. Silk Tassel Bush is native to the coastal range from California to Southern Oregon, particularly at lower elevations.

But if found in the Puget Sound area, it is at the very northern tip of its range and is possibly a cultivar developed for ornamental gardening. Some native species have been cultivated to emphasize specific characteristics attractive to gardeners. Often today, this is achieved through cloning of an especially attractive or hardy individual plant. While these plants may be great for backyard gardens, they do not have the genetic diversity of wild plants. Lack of genetic diversity make the cultivars more susceptible to a whole host of unanticipated problems.

This is where Silk Tassel Bush can become a native plant, or not, for Seattle. Are there places within Seattle where it would be found and other places where it would not, given the particular micro-climate, soil, hydrology, biological interactions, and natural dispersal? Such questions plague restorationists with their complexity, and the answers finally come down to a matter of judgment and opinion.

You will find Silk Tassel Bush listed as a native plant on the Native Plant of the Month posters among the Starflower education materials on the Washington Native Plant Society web page. In Seattle you will find the Silk Tassel Bush often in association with Garry Oak (both were named by David Douglas for Nicholas Garry, a Hudson Bay Company administrator) in Seward Park, for example. But whether to plant this bush in other areas is up to our restorationists.