Pepperweed Cost Share

PERENNIAL PEPPERWEED COST SHARE

Perennial pepperweed (Lepidium latifolium L.) is a hardy perennial plant in the mustard family that spreads by creeping underground roots, known as rhizomes, as well as through it’s prolific seed production. It is a native of southern Europe and western Asia, arriving in this country around 1900 as a contaminant in imported sugar beet seeds. It has since spread throughout all of the far-western states and is found in scattered populations in Washington, the heaviest being in the central part of the state. Perennial pepperweed is an aggressive invader of pastures, riparian zones, and wetter waste areas. It can also be a problem weed in roadside, rangeland and field crop situations, often reaching fields through irrigation ditches from riparian habitats. The creeping root system makes this plant difficult to control by mechanical means alone. Cutting, digging or pulling can serve to increase spread because the broken roots can be stimulated to send up more shoots or start a new colony. With this weed, as with most of the root spreading perennial weeds, it is important to jump on a new patch to get it under control before the root mass and seed bank are overwhelmingly large.

In Stevens County, we know of only a handful of sites where this noxious weed occurs. All of the sites we know about are relatively small (less than one acre, with most being only several square feet) and all happen to be in the central portion of the county. We are concerned that there may be quite a bit more of the weed than we know about. Perennial pepperweed is just one of several white-flowered mustards (most of which are not classified as noxious weeds) and it could easily be overlooked by our staff as well as landowners. If we do indeed find "the mother lode" at some point in the future, our cost share program will likely alter significantly. In the mean time, we’re going to treat this weed as one of the few "new invaders" that we think we can eradicate.

If you suspect you may have this weed or if you think you have seen it somewhere, please contact us! For 2011, we will continue with the cost share program we began in 2002, the key elements of which are as follows:

Key Elements of Perennial Pepperweed Cost Share Program

Weed Board personnel must be given access to the property for surveying, marking, and treatment of the infestation or individual plants as needed the entire season
Cost share treatment will usually be in the form of a herbicide appropriate for the site and plant. If the patch is very small and we feel the entire root system can be readily removed, we may choose mechanical control
Landowners must agree to continue to cooperate and work with us in following years and notify us immediately of a change in property ownership

Goals: 1) maintain consistency with respect to treatment-it is easy to walk away from a patch thinking it’s been controlled or even eradicated just because top growth is gone for one or two years 2) try to eradicate the weed from the property and, eventually, the county.
Perennial pepperweed is required to be controlled by landowners everywhere it is found in Stevens County