Weeds & Invasive Plants

All Weeds & Invasive Plants Content

Flowering Canada thistle distributing seed in a pasture.

Dense Seeding Can Reduce Canada Thistle in Planted Grasslands

Canada thistle is a common invader in grassland plantings. Over the past decade, researchers and land managers have experimented with controlling Canada thistle in planted grasslands through increasing competition from desirable plants.

Three woody plants. From left: Ponderosa pine tree, chokecherry bush and greasewood.

Poisonous Plants on Rangelands: Woody Species

Several woody plant species that are poisonous to livestock are found throughout South Dakota rangelands, including ponderosa pine, chokecherry, greasewood and broom snakeweed.

Solanum ptychanthum plant profile.

Understanding Eastern Black Nightshade: A Comprehensive Guide for Gardeners

Eastern black nightshade is a resilient invasive plant that can thrive in a variety of environments. This resource explores its genus, description, optimal growing conditions, propagation, fruiting period, and methods for safe removal.

A companion planting of kale, pole beans, and marigolds in a small garden plot.

Organic Pest Control Methods

Integrated pest management is an environmentally conscious approach to managing insects, weeds and disease. By focusing on natural processes, growers use pest control methods beginning with the least toxic and amplifying the pest control needs gradually if problems persist.

A red sprayer in a green field with a cloudy sky in the background.

How to Stop Drift

The goals of applying any crop protection products include: increasing effectiveness, mitigating drift, and maximizing profits. We will focus on mitigating drift, even though all three interact with each other.

Two scans of older SDSU Extension publications from 1949 and 1959.

Revisiting Old Lessons in Corn Weed Management: 2,4-D and dicamba

What can past herbicide programs teach us about managing against herbicide-resistant weeds in corn today?

Group of farmers strategizing near a field at sunset.

Now is Time to Plan Your Weed Management Strategy for the 2025 Growing Season

As harvest season comes to an end, now is the time to start formulating your weed management plan for next year. Learn some expert tips for getting your operation off to a good start next growing season.

A farmer observing a field at sunset.

Now is the Time to Plan for Noxious Weed Control in 2025

Since most of South Dakota has experienced several frosts, the opportunities for fall herbicide applications are likely over. Now is the time to plan for noxious weed management for both spring and fall tactics.

Producer with tablet observing a field in late autumn.

Now Is the Time To Make Your Weed Management Plan for the 2024 Growing Season

As harvest season comes to an end, now is the time to start formulating your weed management plan for next year. Learn some expert tips for getting your operation off to a good start next growing season.

Two pictures, both a picture of a green plant in a green pot in front of a orange/brown, brick wall. The left picture has a healthy, tall green leafy spurge plant and the right picture has an unhealthy, short green leafy spurge plant.

Evidence That 2,4-D Alone May Not Effectively Manage Leafy Spurge

The SDSU Extension Weed Science Project is currently conducting a potted plant study looking at various herbicide treatments to manage leafy spurge.