Whitman Mission National Historic Site - Nonnative Species

By 1985, major emphasis for maintenance within the park was being placed on revegetation and the control of exotic plant species. Vegetation management has converted 65% of Whitman Mission from exotic grasses and weeds to grasses that grew in the area during Whitman"s era, or to grasses that have the same appearance as the native grasses. These native-appearing grasses will gradually be replaced with native species by the park staff. A vegetation plan was developed by the park staff and implemented for the area surrounding the visitor center. In 1995, vegetative alternatives were developed for treating exotics on the banks of the irrigation channel. Some implementation has been initiated. In 1997, an inventory of exotic pest plant species identified the following six species of concern: field bindweed, jointed goatgrass, poison hemlock, yellow starthistle, Canada thistle, and Scotch thistle. Control strategies for these species have been developed, and incorporate more extensive use of integrated pest management techniques.