Weeds, Poisonous Plants & Other Pests

Weeds Management & Control

PNW Weed Management Handbook - This handbook is designed as a quick and ready reference of weed control practices used in various cropping systems or site/situations in Oregon, Washington, and Idaho. Because chemical regulation of plant growth is complex and requires considerable knowledge, a large portion of the handbook is devoted to registered uses of herbicides, crop desiccants, and some plant growth regulators. Scroll to the 'Weed Control in Pasture and Rangeland' chapter for commonly used herbicides. Always read the chemical label prior to any application!

Weed Management in Hay Production - Available for purchase through Oregon State University Extension Service, this full-color guide to the most common weeds in hay crops and the herbicides used to manage them. Includes weed identification photos. Describes herbicide effectiveness by weed species and gives characteristics of each herbicide. Outlines weed management program.

Perennial Weed Biology Management - Perennial plants live at least 2 years; some live for decades. Most perennial weeds reproduce both by seeds and by the spread of energy-storing vegetative parts, such as roots or tubers. This combination of reproductive mechanisms makes management of perennial weeds difficult. By understanding how perennial weeds reproduce and spread, land managers are better able to plan a successful weed management strategy.

Perennial Weed Control - For intelligent and efficient weed control, some knowledge of the life cycles of weeds is useful. The life cycle of a weed is simply its seasonal pattern of growth and reproduction. For example, an annual life cycle means that a weed goes from seed to seed in one growing season or one year.

Foxtail Control in Pastures and Hayground - Foxtail is a problematic grass in pastures and hay ground and infestations need immediate attention. This fact sheet covers reasonable treatment regimes to tackle infestation.

Management Guides for common pasture weeds:

Blue Mustard Himalayan Blackberry
Catchweed Bedstraw Meadow Knapweed
Common Groundsel Red Sorrel
Creeping Buttercup Velvet Grass
Curly Dock Western Brackenfern
Downy Brome Wild Carrot 
Field Bindweed Yellow Starthistle

 

 

 

 

 

 

Poisonous Plants: 

Poisonous Plants Encountered in Oregon - A list of plants that have been known to cause toxicity issues in livestock.  Includes ornamental plants, shrubs and trees.

Poisonous Plants to Livestock - Table of poisonous plants and the species it affects, inluding the scientific name, common name, poisonous parts of the plant, and the primary poisons.

Poisonous Plants Commonly Found in Oregon Pastures - In-depth information about poisonous plants found in pasture areas.  Includes detailed toxicity definitions and colored photos of common weeds.

Western Washington Plants Known to Be Poisonous to Horses - Table of plants that are known to be poinsonous horses.

Other pests that affect pastures:

Moss in Pastures - Soil fertility is often one of the key factors of moss infestations in pastures. In many cases, providing appropriate nutrients will allow grasses and legumes to crowd out the moss.  Read this article to learn more.

Armyworms in Grass Pastures and Corn in Western Oregon Armyworms are a serious pest of turf, forage and seed grasses; small grains and corn throughout North America. This publication discusses identification, life cycle, monitoring, action thresholds, biological control, organic controls, and chemical controls of armyworms. Includes color photos for identification.

Endophyte Toxins in Grass Seed Fields and Straw - Grazing animals on grass seed fields and feeding grass seed straw can be advantageous to both livestock producers and grass seed growers. Problems may develop, however, if livestock consume varieties of tall fescue and perennial ryegrass that are intended for use as turf. Some turf varieties are infected with an endophyte, which produces toxins harmful to livestock.