Get It While The Getting Is Good March 1, 2019 By John Daniels, agronomist, Central Region

Postemergence herbicides are most effective when weeds are still small. 

Timing and persistence are the keys to successful weed control. When it comes to post-emergent treatments, this means applying the product as soon as weeds begin to appear.

Mature, established weeds are always going to be much more difficult to eliminate compared to juvenile weeds. Therefore, spot treatments should be made at the first sign of weed invasion. This principle holds true regardless of which specific herbicide chemistry is selected or what weed is being targeted. Delaying post-emergent treatments until after weeds are mature will often necessitate additional applications to achieve the desired level of control.

The longer weeds are left to grow unencumbered, the more space they will occupy. This means more time will be required for turf to fill in the voids created after weeds die. If weeds are eliminated when they are small, voids in the turf canopy will be hardly noticeable.

Dauber-style applicators are ideal for targeted spot treatments. Or you can make your own version by simply attaching a bingo marker to a dowel rod. These effective, low-cost tools can deliver an effective rate of herbicide with pinpoint accuracy making them perfect for controlling small weeds such as Poa annua. An employee can quickly daub a dozen plants in a matter of seconds. Applications can even occur on windy days with no fear of drift.

The ability to make precise applications also provides the opportunity to utilize a wide range of herbicide chemistries. Non-selective herbicides, that would otherwise injure turf, can be incorporated as part of the weed management program. This flexibility can improve weed control and help to lessen issues with resistance from developing.


Central Region Agronomists:

Bob Vavrek, regional director –

John Daniels, agronomist –

Zach Nicoludis, agronomist –

Information on the USGA’s Course Consulting Service 

Contact the Green Section Staff

PDF Version

More From The Central Region