Weeds & Invasive Plants

All Weeds & Invasive Plants Content

Two poisonous rangeland plants. Left: Woolly Locoweed. Right: Lambert Crazyweed (Purple Locoweed).

Poisonous Plants on Rangelands: Locoweed and Crazyweed

Locoweed and crazyweed are found throughout South Dakota rangelands, and both can cause livestock poisoning.The names locoweed and crazyweed are often used interchangeably. However, there are notable differences between the species.

Low larkspur and twogrooved poisonvetch plants growing in rangeland.

Poisonous Plants on Rangelands: Larkspur and Poisonvetch

Larkspurs are the second leading cause for all livestock deaths from toxic plant poisoning. Poisonvetches are considered accumulator plants that uptake excessive levels of selenium and cause toxicity problems in cattle.

a sprawling green plant with flowering yellow heads

Sweet Clover Poisoning

Hay that contains sweet clover can be an excellent feed as long as the dicoumarol level is known and feeding management is used to prevent poisoning.

A lush, green lawn with a few scattered weeds throughout.

Use Caution With Turf Herbicide Applications During Extreme Heat and Drought

Dry conditions cause weeds to be under stress. This decreases herbicide effectiveness with annual, biannual and perennial plants. So, is there a safe option for weed control in yards during high temperatures and dry conditions?

Canada thistle growing in a pasture.

Noxious Weeds of South Dakota

Pictorial reference guide of noxious weeds in South Dakota

Paul O. Johnson giving a presentation near a research plot.

Paul O. Johnson Retires After Dedicated Career in SDSU Extension

June 08, 2022

Paul O. Johnson, SDSU Extension Weed Science Coordinator and Northeast Research Farm Coordinator, is retiring after a dedicated 33-year career supporting the people of South Dakota in his role at SDSU Extension.

Crop sprayer and a bottle of chemicals in a yard.

Read the Label

Last year, Bayer announced they would be phasing out glyphosate from the homeowner market, but they would be keeping the Roundup name for future marketing. Learn some important label considerations when purchasing Roundup-branded products.

A close up of prickly Russian thistle

Prickly Russian Thistle

Publications that provide introductory and expanded information on the notorious invasive plant, prickly Russian thistle.

Four common spring weeds: Shepherd’s Purse, Catchweed Bedstraw, Waterpod and Henbit.

Spring Annual Weeds

There are several weeds that pop up very early in the spring and start flowering before most other plants have shown any signs of growth. Learn about some common varieties to look out for.

A small pile of harvested non-gmo soybeans on a grey cloth.

Want a Premium Price? Weed Control In NON-GMO Soybeans

Many emotions set in on farmers that hear the word “non-GMO”, but it could help them in times like today when prices are low for many farm products in South Dakota.