Douglas County Weed Management

Welcome to the Douglas County Weed Management Website.


The Pacific Northwest Weed Management Handbook, "Control of Problem Weeds" page has been updated!  This website give information regarding specific weeds that may be troublesome to control. Herbicides and/or rates listed cannot necessarily be used on cropland. Rates of application and restrictions vary depending on crop or site. Do not apply to a crop or site not listed on the label.

Control of Problem Weeds

In October 2004, Douglas County Commissioners activated the Douglas County Weed Management Task Force and appointed nine individuals who geographically represent Douglas County agriculture and urban areas. Margaret Viebrock, WSU Extension, was appointed to facilitate this committee and help to develop weed management strategies.

Ex-officio members of this Task Force include representatives from Douglas County Transportation and Land Services, Foster Creek Conservation District, Douglas County Commissioners and WSU Extension.

Task Force Directives (defined by the Douglas County Commissioners)

  • Develop a communication system with all entities that have weed control programs.
  • Gain a better understanding of weed control methods used by other other entities.
  • Design a system to coordinate weed control efforts.
  • Continue the process of developing an informed educational approach to weed management in Douglas County.
  • Engage landowners and agencies in a cooperative weed management program.


Since the appointment of the Douglas County Weed Management Task Force, the committee has taken a proactive approach to learn about various weed management programs. Members have met with agency people, integrated weed management program managers, state weed board representatives, county noxious weed control managers and other groups who manage weeds. The best parts of these programs have been integrated into the local plan of work. Members have also spent time in Olympia with state legislative groups explaining how the program has been successful in Douglas County.


Hoary Cress

Hoary Cress

Hoary Cress

Hoary Cress Facts

  • This Perennial Mustard was introduced from Europe, Asia and Northern Africa.
  • Plants emerge in very early spring.
  • Hoary cress is typically found on open, unshaded, disturbed ground. It grows well on alkaline soils that are wet in late spring and does better in areas with moderate amounts of rainfall. It can also be found widespread in fields, meadows, pastures, croplands, and along roadsides (FEIS 1996).
  • Generally considered unpalatable to livestock. Often spread as a contaminant of alfalfa hay.
  • Toxic: humans, livestock; plants may cause digestive tract irritation.
  • Blue-green, lance-shaped leaves alternate along the stem. Lower leaves are stalked, while upper leaves have 2 lobes clasping the stem.
  • Numerous white flowers with 4 petals give the plant a white, flat-topped appearance.
  • Seed capsules are heart-shaped and contain 2 reddish brown seeds.
  • Mode of reproduction is by seed and vegetatively from roots.
  • One plant can produce 1,200 -4,800 seeds.
  • 84% of seed produced are viable the first season (Mulligan and Findlay 1974; FEIS 1996). Buried seeds can remain viable for 3 years (Sheley and Stivers 1999).
  • Once established, hoary cress is a highly competitive weed capable of spreading primarily by roots. It can be highly competitive with native vegetation on rangelands.
  • Other common names: Whitetop, heart-podded hoary cress.

Rosette plants and Early bolting
Rosette plants and Early bolting

Why is it a Noxious Weed?

Hoary cress is a highly competitive plant forming a monoculture, and once established, it easily displaces native vegetation. It has the potential to reduce the value of high-price wheat lands.

How do I control it?

Fire: Fire may enhance hoary cress populations by setting back other vegetation because the plant rapidly re-sprouts from rhizomes or establishes from seeds.

Mechanical: Mechanical removal (i.e. tillage) is strongly discouraged. Small, broken root fragments that are left behind will form a new plant that will produce many more plants. Mowing 2-3 times a year for several years may slow the spread and reduce seed production. The optimum time for mowing is during the bud stage. Mowing should be repeated when the plants re-bud.

Herbicide: Please refer to the PNW Weed Management Handbook or contact your local WSU Extension office or local chemical provider for specific chemical recommendations.

Biological: None currently available.