Weeds & Invasive Plants

All Weeds & Invasive Plants Content

Waterhemp growing at the edge of a soybean field nearing harvest.

Row Crop and Noxious Weed Surveys

Controlling noxious weeds and weeds in row crops is a challenge every year. SDSU Extension has created two online surveys to capture the current climate of weed control in South Dakota.

Leafy spurge growing along the edge of a field.

Leafy Spurge Control in the Fall

Leafy spurge is a difficult-to-control, noxious weed in South Dakota. Spring and fall herbicide applications are critical for leafy spurge management.

Canada thistle growing along field’s edge.

Canada Thistle Control in the Fall

Canada thistle begins to transport assimilates and nutrients down its roots in the fall to survive the winter months. Now is the time to consider a fall herbicide application to keep it under control.

Absinth wormwood growing in a field.

Absinth Wormwood Control in the Fall

Absinth wormwood is a difficult-to-control, noxious weed in South Dakota. Now is the time to consider fall applications for absinth wormwood control.

Yellow toadflax in the reproductive-flowering stage.

Yellow Toadflax Control

Yellow toadflax is a short-lived perennial plant that infests pasture and rangeland. If not controlled, it can displace native plant species and increase the potential for soil erosion. Learn some tactics for managing it.

Long, sharp bracts on a flowering female Palmer amaranth plant.

Palmer Amaranth Infestations Have Been Reported in South Dakota

Recent reports of Palmer amaranth infestations are concerning due to its aggressive growth, seed production, and resistance to multiple herbicide groups. Learn some management tactics to help control it before it becomes a serious problem.

Bird's eye view of Dakotafest

SDSU Extension booth at 2023 Dakotafest to feature livestock, soil and range experts

August 07, 2023

South Dakota State University Extension experts will be at the 2023 Dakotafest to provide information on a range of agricultural and economic issues, from the use of prescribed fire to livestock to weed and soil management.

Common ragweed and kochia growing along a road ditch.

Late-Season Weed Management

At this time during the growing season, many herbicides cannot be applied to crops in the reproductive growth stage. However, weed management can still be implemented. Learn some expert tips for controlling late-season weeds.

Yellow wheat field with green weeds throughout.

At-Harvest and Post-Harvest Weed Management Tactics in Wheat

Many pre and postemergence herbicides did not adequately control weeds during the 2023 growing season due to early dry and hot conditions. Despite the poor control, there are still options to implement at-harvest and post-harvest to help manage weeds.

Green soybeans with a few green weeds throughout.

The Value of a Preemergence Herbicide After a Dry Period During the Growing Season

Preemergence herbicides are an essential component of weed management, even when early season weather isn't cooperative. Learn about some of the benefits they can offer following a dry growing season.