Max Gallaway
DUNCAN — Warm weather really turns our thoughts and planning to outside activities, which includes having that perfect lawn, with lush thick grass and no unsightly broadleaf or grassy weeds.
As we choose herbicides to use in our lawn, there are many considerations before a product should be used. First, it is important to determine what types of weeds you are trying to control. Remember, a weed is simply a plant growing out of place. Second, consider the type of turf in your lawn and its tolerance to a herbicide. Third, can the herbicide have the potential to cause injury to other ornamental plants in the lawn?
Take time once you have found a product you plan to use and read the label. It will give you all the needed information to prevent any unwanted outcome.
From now until mid-March is a good time to put down a pre-emergent herbicide to control crabgrass. A pre-emergent herbicide kills crabgrass as the seeds germinate in the soil. Pre-emergent herbicide products need to be watered in with 1/2 to 1 inch of water by rain or sprinkler to move the product where the weed seeds are and to activate the herbicide.
Here is a listing of some of the commonly used pre-emergent herbicides. The trade name is listed first. The common chemical name is in parenthesis and is listed in small print on the product label under “active ingredients.” Your favorite store that you purchase your lawn products from may have different trade names. Any of these products will be just as effective, so take time to look for the active ingredients on the label.
Surflan 4AS (oryzalin) –Provides a broad spectrum of broadleaf weed control in addition to crabgrass and sandbur control. Incorporation and activation is necessary within 21 days of application with 1/2 inch of rain or by watering.
Balan (benefin) – One of the active ingredients found in several products. Best applied in early March due to a shorter time of herbicide activity than other compounds.
XL (benefin and oryzalin) – A combination of Balan and Surflan. Activation is necessary within 21 days of application with 1/2 inch of rain or irrigation.
Team (benefin and trifluralin) – A combination of Balan and Treflan. Water in a few hours after application.
Barricade (prodiamine) – Provides the longest control, but it needs to be activated with at least 1/2 inch of water and preferably with closer to 1 inch of water within 14 days of application.
Dimension (dithiopyr) – It is the only post-emergent with action on young crabgrass, as well as pre-emergent activity.
This is also the time we see winter broadleaf weeds emerge such as henbit and wild geranium. These plants can be controlled with several different post-emergent products:
Banvel, Dicamba 4L, K O G Weed Control (Dicamba)
Later summer broadleaf weeds can be controlled in April and May with post-emergent products containing 2,4-D, there are many trade names, 2,4-D + Dicamba, also many trade names and product containing 2,4-D and a combination of other chemicals such as Super Trimec, Weed-B-Gone or Weedestroy.
There are many products on the market that are available to homeowners wishing to do their own weed control. Once again, take the time to study the labels to determine which product you will need to use. For more information, give me a call at 580-255-0510.
— Max Gallaway is the Oklahoma State Extension educator for agriculture for Stephens County. He can be reached by calling 580-255-0510.