One of the most challenging problems for a golf course manager is keeping weeds out. Regardless of the region or seasonin the US, a major priority for every golf course manager is to make sure that weeds do not take over a golf course.

Weeds are plants that are deemed unacceptable because they interfere with the livelihood of humans.  On golf courses, weeds can be found on greens, tees, fairways, rough areas, and even in the water features. Weeds are often unsightly, can make the golf course unplayable, and require substantial investment to managethem and prevent their spread. If weeds are not properly managed, they can affect the condition of the golf course and impact golfing.

How do you manage weeds on a golf course?

There are several weeds that infest golf courses some of which are more problematic than others. The most critical step in managing golf course weeds is proper identification. Golf course superintendents must be able to identify the weed species they are trying to control before selecting an appropriate management strategy to implement. Weed identification is important because control strategies can vary between weed species.

• For example, crabgrass and tropical signalgrass look similar in turfgrass but postemergence herbicides used for control are different for each weed species. Many land grant universities provide numerous online resources that help with identifying weeds.

When identifying weed species, golf course superintendentsshould familiarize themselves with specific characteristics of the weeds such as their lifecycle. Knowing the life cycle will help them understand how a weed species reproduces and spreads which will help identify vulnerabilities to exploit with targeted management strategies.

• For example, crabgrass is an annual species that reproduces only by seed, whereas tropical signalgrass is a perennial that reproduces by seed and vegetatively via stolons.Weed control tactics for annual weeds are different from those used for the control of perennial weeds.

What are some challenging golf course weeds?

The most challenging golf course weeds are grasses or grass-like weeds that can blend in with turfgrass in greens, tees, fairways, and roughs and become problematic if left uncontrolled. Some of the most commonly problematic species include:

• Annual weeds, e.g., annual bluegrass, crabgrass, and goosegrass. Annual weed species reproduce via seed and implementing an effective control strategy requires golf course superintendents to use:
  1. Control tactics that prevent/minimize weed seed production.
  2. Preemergence control strategies to prevent weed emergence.

• Postemergence control strategies to prevent weeds that escape preemergence control from becoming established and producing seed.

• Perennial weeds,g., bermudagrass, dallisgrass, green kyllinga, nutsedge, perennial ryegrass, and tropical signalgrass. Perennial weed species reproduce via seed and vegetative structures and implementing an effective control strategy requires golf course superintendents to use:
  1. Control tactics that target the vegetative reproduction capabilities of the weed.
  2. Preemergence control strategies to prevent weed emergence.

• Postemergence control strategies to prevent the establishment and spread of the weed species.

Golf course weed management in 6 steps

To stay ahead of weeds and prevent them from becoming established and requiring huge investment in resources and management, here are 6 steps golf course superintendents can adopt.

1. Understand the enemy
   • Knowing the life cycle traits and habits of a weed species is key to knowing vulnerabilities that can be exploited for good management.
2. Select the most effective products
   • Choosing the right herbicide to control the weed(s) being targeted. Superintendents need to select products that are safe to use on the turfgrass species.
   • Choosing the right adjuvants that improve control with herbicide. For example:
     • Use of a wetting agent, penetrant, and activator, e.g., Cide-Kick™ or Brewer 90-10™.
     • Use of a water conditioning agent, e.g., AquabupH™ or Brewer’s Water Conditioner™.

3. Use effective herbicide rates
   • Use label rates for the best control and to minimize the number of weeds that escape control.
4. Use multiple sites of action herbicides
   • This is a strategy that is designed to prevent or delay the onset of herbicide resistance. When the same herbicide is used repeatedly for a long time the development of resistance is likely to happen. By varying weed control tactics to include herbicides with different sites of action, the development of resistant weeds will be slowed down or prevented.
5. Apply herbicides at the proper time
   • If herbicides are applied at the wrong time, a window of opportunity for weed control may be missed allowing the weeds to establish and spread.
6. Develop a long-term weed management strategy
   • After evaluating which weed management tactics work best, superintendents need to develop strategies that minimize weed establishment and spread, slow down the development of herbicide resistance, and are safe to use on turfgrass.

Further reading

• Cide-Kick II for Excellent Management of Weedy and Invasive Plants.
• Brewer 90-10 Surfactant for Excellent Vegetation Management.
• Everything You Need to Know About Agricultural Wetting Agents.
• Staying a Step Ahead of the Soil Seedbank.
• How Does Water Quality Affect Vegetation Management?
• Late Season Control of Perennial Weed Species.
• Pest Biology and Ecology on Your Land.
• Pesticide Resistance Management.

References

• Brosnan, J. 2015. Golf’s Most Common Weed-Control Challenges. United States Golf Association – Green Section Record 53: 12. (Accessed Oct. 1, 2022).