Why is this weed here? Weed Management in Pasture Systems

Marcelo Wallau, UF/IFAS Forage Extension Specialist, in collaboration with Brent Sellers (UF/IFAS RCREU), David Russell (Auburn University)

 

As a Forage Extension Specialist in Florida, about half of the questions I get are about weeds. “What is this weed and how can I kill it?” is all people want to know. (I should have been a weed scientist!). However, seldom do people ask, “Why is this weed here?” or how to manage weeds rather than just controlling them.

In a recent Cow Talks Podcast episode, Chris Prevatt and I spoke with Dr. Brent Sellers (UF/IFAS) and Dr. David Russell (AU/AL Cooperative Extension) about integrated weed management—a timely topic as we move into spring. Dr. Russell emphasized that the foundation of weed management is a healthy forage stand that competes with encroaching weeds. This includes cultural practices like maintaining proper soil fertility and grazing management. Dr. Sellers pointed out that many weed problems are “man-made,” often stemming from management gaps that create opportunities for weeds to establish. He highlighted common ways weeds spread, including contaminated feed, weedy hay, dirty equipment (especially mowers), and a lack of property boundary weed control, allowing weeds to spread from neighboring areas.

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Understanding Weed Control vs. Weed Management

Weed control, as it is commonly understood, typically involves chemical (herbicide) or mechanical (mowing, tilling) methods. While these tools are effective, they are just one part of an integrated weed management plan. Weeds are always going to be present, but they may not always cause negative impacts. When weed populations increase to a point where they are impacting our pastures, you should be asking yourself questions.  If we can understand what caused them to be there in the first place and successfully spread afterward, we can better act on the problem, reduce the cost of control, and ultimately improve our pasture management.

To summarize, in this video, Dr. Sellers explores some of the principles of weed management in pastures in Florida:

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Prevention

Prevention is the first step—hence the key question, “Why is this weed here?” In pastures, weed encroachment usually results from a combination of factors. The primary contributors include stress on the forage stand—such as overgrazing or poor fertility—which weakens desirable plants and creates space for weeds to establish. Additionally, weeds often spread through contaminated hay, feed, equipment, or low-quality seed used for overseeding winter forages. Addressing only the weeds themselves, without fixing the underlying conditions, is unlikely to lead to long-term success. The priority should be improving pasture conditions to support forage growth while minimizing pathways for weed introduction. Considering prevention as one of the main (and first) integrated weed management practices, below are three common examples of how weeds can be brought into your pasture.

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Weed ID

Next, proper weed identification and timing are essential for an effective weed management plan. Consider:

• What type of weeds are present? (Annual or perennial? Broadleaf, grass, or sedge?)
• When is the most effective time for control? (Different weeds require different approaches.)

Since herbicide application is very site-specific, it is hard to issue blanket recommendations. However, both UF/IFAS and Alabama Cooperative Extension systems have excellent resources on weed management in pastures and will provide more direct recommendations on herbicide application strategies. Similarly, Dr. Russell’s video below provides more in-depth insights into spring weed management for pastures and hayfields in Alabama.  We encourage you to contact your local extension agent for site-specific recommendations, as management strategies vary by weed species and local conditions. Above all, always follow the directions on the herbicide label, as those are the official recommendations.

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Shifting the Mindset: From Killing Weeds to Managing Pastures

When we shift our mindset from “how to kill this weed” to “how to manage my pasture (and weeds),” we will set ourselves up for better results. Sound pasture management—maintaining soil fertility, balancing grazing pressure, and preventing weed introduction—which reduces reliance on reactive weed control measures.  For more support on weed management for your propriety, contact your local extension agent (UF/IFAS) or regional extension agent (AL Cooperative Extension), or email the Forage Team at forages@ifas.ufl.edu.