Weeds & Invasive Plants

All Weeds & Invasive Plants Content

Green Canada thistle with whitened leaves at the top. Various green plants throughout.

White Thistle Disease: Biological management at work

White thistle disease can be seen among many Canada thistle plants throughout South Dakota this growing season. Plants infected with the disease exhibit significant reductions in both growth and seed head compared with non-infected plants.

A picture of a green, smooth crabgrass plant with a white background.

Late-Season Crabgrass Control

At the start of August, crabgrass is often prevalent in lawns. Ideally, this weed should be controlled earlier in the season, but if early management was missed, a post-emergence herbicide can help control it before it produces more seed.

Two pictures of green soybeans with a blue sky in the background.

Strong, Effective Herbicide Programs Can Be Complimented With Narrow Row Spacing

While strong herbicide programs will result in effective weed management, a cultural tactic, such as row spacing can result in a complementary increase in effectiveness.

United States Environmental Protection Agency Sign plate outside the agency’s main office.

EPA Proposes a Decision to Approve Registration for Dicamba Labeling to Be Applied to Tolerant Soybean

Dicamba products previously labeled for overtop application to tolerant soybean are not registered for use during the 2025 growing season. However, the EPA has proposed to re-register these dicamba products for use in tolerant soybean starting in 2026.

A photo of a winter grazing pasture with a variety of grasses, shrubs and forbs that was taken at the SDSU Cottonwood Field Station that contains some field pennycress.

2025 Field Pennycress Management Considerations

Field pennycress prevalence on pastures has been observed to be in higher abundance this year in Western South Dakota. When consumed in certain quantities it can be toxic to livestock.

Many green soybean plants within a field that has brown grass and residute.

Burnt Soybeans Look a Lot Better Than Weedy Beans!

Prior to the introduction of Roundup-Ready soybean, growers were accustomed to soybeans exhibiting short-lived herbicide injury. While soybean plants may look unsightly from a PPO-inhibiting herbicide application, a more unsightly view is a soybean field full of weeds.

A green absinth wormwood plant surrounded by other green vegetation.

Absinth Wormwood Spray Window Passed: Mow now and plan to treat the regrowth in the fall

Absinth wormwood is a statewide noxious weed that inhabits cropland, pasture, rangeland, right-of-ways, and waste sites. If not effectively managed, the species can displace desirable vegetation, reduce crop yield and decrease land value.

Corn and soybean fields with abundant weeds growing throughout.

Inexpensive and Simple Herbicide Programs in Corn and Soybean Will Not Be Effective

While selecting an inexpensive program with only one active ingredient in each application may be tempting due to the current agricultural economy, the result will likely be a more expensive problem in the future.

Rows of empty white, plastic pesticide containers.

2025 Pesticide Container Recycling

The South Dakota Department of Agriculture and Natural Resources is again offering pesticide container recycling services across the state. View a complete list of 2025 dates and locations.

Green waterhemp plant next to a black, ink pen. Green soybeans in the background with brown soil in the foreground.

Waterhemp is flowering. No seeds present yet.

Waterhemp is one of the most-difficult weeds to manage in South Dakota row crops. While herbicide resistance is a great factor in the difficulty of managing this weed, the biology of the species plays an important role as well.