Weeds & Invasive Plants

All Weeds & Invasive Plants Content

A few small, green weed plants among a background of brown dirt, tan crop residue and green soybean plants.

Excess Moisture and Heat Will Likely Increase Weed Growth and Germination

With warmer temperatures on the horizon, crop growth and development is set to rapidly increase, and so is weed growth and germination. Learn some expert tips for scouting and managing later-emerging weeds.

Full plant profiles: Golden alexander and wild parsnip.

Plant Look-Alikes: What’s the Difference Between Golden Alexander and Wild Parsnip?

Golden alexander (Zizia aurea) is a striking native plant in South Dakota. However, another plant in this region often mistaken for golden alexander does not belong here and contains a harmful toxin.

Picture of multiple green plants and tan, corn residue with brown soil in the background.

Reminder: One herbicide in the postemergence application will likely not be effective

The SDSU Extension Weed Science Project is currently conducting a plethora of field research evaluating weed management in soybean. One study is investigating the effectiveness of 2,4-D and tank mixtures applied one time to 4-inch weeds.

Small, green weeds throughout with a brown yard stick showing the weeds’ height being 2.5 inches.

Postemergence Herbicide Applications Need to Happen Soon in Soybean

In soybean crops, postemergence herbicides should be applied to smaller weeds, but proper scouting is likely necessary before application. Learn everything you need to know before making an application this growing season.

Plant Look-Alikes: What’s the Difference Between Phlox and Dame’s Rocket?

Distinguishing between native phlox flowers and the invasive dame's rocket can be challenging due to their similar appearances. Learn some key characteristics that can help you tell dame's rocket apart before it invades your property.

Left: Fireweed growing in a clearing. Right: Purple loosestrife growing in a meadow.

Plant Look-Alikes: What’s the Difference Between Fireweed and Purple Loosestrife?

Fireweed and purple loosestrife are often confused with one another due to their similar appearances, but the two plants have dramatically different impacts on the environment. Learn some key characteristics to help tell them apart.

Green plant with bright yellow flowers throughout.

Leafy Spurge Management in the Early Summer

Early summer and fall integrated management tactics are critical for leafy spurge management. Now is the time to consider implementing early summer management tactics for leafy spurge.

A red, tractor-mounted sprayer with its tank being flushed by a hose connected to a large truck.

Dicamba Cannot be Applied Postemergence in Dicamba-Tolerant Soybeans After June 20

With weather delaying the planting of soybean, the clock is ticking to spray dicamba before the cutoff date of June 20, 2024. Learn what application tactics might work best before the deadline.

Tractor applying postemergence herbicide to a corn field early in the growing season.

Considerations of Corn Postemergence Herbicides

Managing weeds after emergence is important to protect the yield potential of corn crops. Learn some important application considerations before selecting a postemergence herbicide.

Two pictures of bright, green plants with yellow flowers.

Leafy Spurge or an Imposter?

Leafy spurge is a statewide noxious weed that can be difficult to manage. However, are the recent yellow flowers appearing throughout South Dakota landscapes leafy spurge or another species?