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Preventative Herbicides Curtail Pesky Weeds

Prevention is always the best method when it comes to controlling lawn weeds.

Hot Springs, Ark. – Prevention is always the best method when it comes to controlling lawn weeds.  The most effective way to control weeds in a lawn is a dense vigorous turf.  Any practice that helps produce thick turf discourages weeds.  Often, eliminating tough weeds requires a little extra help. That’s where certain herbicides come in to play.

For control of broadleaf weeds after they emerge, one of the preferred choices are the Trimecs or phenoxy herbicides.  These include 2,4-D, dicamba, dichlorprop, MCPA, mecoprop and carfentrazone, or various combinations of these.

Phenoxy herbicides are formulated specifically for broadleaf weeds and have very little effect on most grasses.  These herbicides must be used at the right time.  Phenoxy herbicides should not be used on your warm-season lawn during the spring green-up period because injury to your lawn may occur.  Also, waiting to long can require more herbicide to control weeds, plus the damage has already been done allowing the weeds to set seed. 

Various three-way combinations of phenoxy herbicides such as Trimec Classic, Super Trimec, Trimec Southern, and Weed-B-Gon are more expensive, but they will control a larger spectrum of broadleaf weeds than one herbicide alone.  Careful distribution of these herbicides is also important.  In other words, make sure the application doesn’t drift to other plants.  Plants such as tomatoes, okra, roses and many shrubs may be injured or killed from drift of these herbicides.

Phenoxy herbicides should be applied when there is good soil moisture and the weeds are small – about a two- to four-leaf stage.  Also, the temperature should be at between 60 to 90 degrees for eight to 10 hours.  To avoid dilution or runoff, apply the herbicide when there is no rain in the forecast for the next 24 hours.

2,4-D products are best for control of wild garlic, dandelion, henbit, chickweed, plaintain, dock species and other broadleaf weeds.  A higher rate of application may be required for persistent wild garlic.

Applying 2,4-D with other herbicides increases its potency.  Using 2,4-D in combination with dichlorprop, mecoprop, dicamba, MCPA or carfentrazone on most annual and perennial broadleaf weeds does a better job than 2,4-D alone.

As with all herbicides, read and follow label directions and precautions before use.  To clean a sprayer after using a phenoxy herbicide, wash it with soap and water.  Then put 3 tablespoons of ammonia per gallon of water in the sprayer and let it sit for 24 hours.  Rinse the sprayer again before the next use.  Clean equipment can make the difference between success and failure.  You should not use a sprayer that has had a lawn herbicide used in it to spray an insecticide or fungicide on your vegetables, trees, shrubs, or flowers.  You could kill or damage these plants if you do.

Herbicides require careful use and management, but the results are well worth the effort.  Spraying isn’t the only answer, either: weed prevention starts with good lawn management.  Herbicides only aid cultural methods such as proper fertilization, a neutral PH and a proper mowing height.  For more information on herbicides and proper application, contact me at the Garland County Extension Office at 623-6841 or email me at 

EHC Information

Would you be interested in joining an existing Extension Homemakers Club? How about forming a club in your community?  EHC is the largest volunteer organization in the state. For more information about how you can be involved in EHC in Garland County, call 623-6841 or email Jessica Vincent at

4-H Information

If you’re between the ages of 5 and 19, you can join 4-H! We have a club for you, or you and a group of friends can organize a club of your own.  For more information on the 4-H program call the Cooperative Extension Office at 623-6841 or 922-4703 or email Linda Bates at

Master Gardener Information

If you have an interest in gardening of any type, or would like to learn more in the horticulture field, the monthly Master Gardener meetings are held the 3rd Thursday each month at the Elk’s Lodge and are open to the public and guests are always welcome. For information call the Garland County Cooperative Extension office at 623-6841 or 922-4703.


The Arkansas Cooperative Extension Service is an equal opportunity/equal access/affirmative action institution.

By Allen Bates
County Extension Agent - Agriculture
The Cooperative Extension Service
U of A System Division of Agriculture

Media Contact: Allen Bates
County Extension Agent - Agriculture
U of A Division of Agriculture
Cooperative Extension Service
236 Woodbine Hot Springs AR 71901
(501) 623-6841

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  • The Arkansas Cooperative Extension Service is an equal opportunity/equal access/affirmative action institution. If you require a reasonable accommodation to participate or need materials in another format, please contact your County Extension office (or other appropriate office) as soon as possible. Dial 711 for Arkansas Relay.

    The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.