The Clackamas County Soil and Water Conservation District’s WeedWise Program recently participated in a Spurge Laurel field tour in cooperation with partners from the Four County Cooperative Weed Management Area (CWMA). The event was hosted by West Multnomah SWCD and was attended by land managers from throughout the Portland metropolitan area. WeedWise Program staff were on hand to share our experience in controlling this species in Clackamas County over the last several years.
Spurge Laurel is a small evergreen shrub that was originally introduced into our area as a garden ornamental. This invasive shrub escaped cultivation, becoming established in natural areas throughout the Willamette Valley. This species has been listed as an Oregon class B noxious weed due to its ability to invade forest understory and open grasslands. (Learn more about the effects of invasive plant species.)
Spurge Laurel is easily spread great distances by birds that eat the small dark purple berries. We also see this plant spread when yard debris has been disposed of improperly, such as dumping it into natural areas.
Spurge Laurel is of concern in Clackamas County for two reasons. First, it replaces understory vegetation and prevents natural forest regeneration. Spurge Laurel will invade an area and crowd out young tree seedlings typically found in the forest understory. As older trees die, the young trees that would replace them have been removed from the system, allowing Spurge Laurel to quickly dominate the system.
The second reason for concern with Spurge Laurel because it poses a threat to human health. The sap of Spurge Laurel can cause severe rashes and skin irritation. This is particularly a problem when plants are cut or broken. Anyone handling Spurge Laurel should wear gloves, long sleeves, and pants for protection. The sap can also volatilize, especially during hot weather, so folks should avoid breathing fumes from cut plants as the fumes can cause respiratory difficulty.
Participants on the field tour also learned about controlling this invasive weed. Small plants can be hand pulled, while larger plants require cutting and targeted herbicide use. Control does require multiple years to achieve eradication. The WeedWise Program currently offers free control of this species throughout Clackamas County. If you see Spurge Laurel, or have infestations on your property, please contact our WeedWise Program for assistance.