When I answered the phone at Backyard Farmer this past week most of the callers asked “How do I get rid of DANDELIONS, CLOVER, and /or HENBIT”. I told them the best time to control most weeds was in the fall. They said, “I know that. BUT WHAT CAN I DO NOW?”

They want to do something now and not wait. We get impatient. My product of choice for controlling perennial broadleaf weeds (DANDELIONS, WHITE CLOVER, WILD VIOLETS, AND CREEPING CHARLEY (Ground Ivy)), and summer annual weeds (SPURGE, KNOTWEED, PURSLANE, AND OXALIS), and winter annual broadleaf weeds (HENBIT, CHICKWEED, AND SHEPHARD’S PURSE), is a Trimec formula (3-way herbicide) containing TRICLOPYR. The other two chemicals are usually 2-4-D and Dicamba. This product will not kill Crabgrass.  

According to the University of Nebraska-Lincoln Turfgrass Science Program, the best time to control both perennial broadleaf weeds and winter annual broadleaf weeds in Nebraska is September and October.

“In the fall as perennials (DANDELIONS, WHITE CLOVER, WILD VIOLETS, AND CREEPING CHARLEY (GROUND IVY), prepare for winter, energy reserves are moved from the leaves down to the roots. If herbicides are applied at this time the herbicide will also be translocated to the roots resulting in more effective control. This is why fall herbicide applications are far more effective than spring applications for controlling perennial broadleaf weeds. Even applications well into October are very effective by the following spring. Three-way herbicides (2,4-D plus MCPP plus Dicamba), triclopyr, or fluroxypyr are most effective”

“Winter annual broadleaf weeds germinate in the fall, produce seed the following spring, and die out with the first hot temperatures of summer.  HENBIT (has the little purple flower), CHICKWEED, and SHEPHARD’S PURSE are all examples of winter annuals in turf. Application timing should be similar to perennial broadleaf weeds. Spring herbicide applications are generally not necessary, or effective, since the weeds are near the end of their life cycle.”

“Summer annual broadleaf weeds complete their lifecycle within one growing season. Summer annuals germinate in the spring, flower, and produce seed early to mid-summer, and die following the first hard frost in the fall. Common examples are SPURGE, KNOTWEED, PURSLANE, AND OXALIS

·        “Summer annual broadleaf weeds can be difficult to control. Depending on conditions or species these weeds may germinate at multiple times during the summer and mature very quickly. As a result, a single herbicide application will control only a few of the summer annuals since the others either have not germinated or have grown too large to be controlled. In addition the summer annuals have a waxy layer on their leaves to prevent water loss, which will also limit herbicides from entering the leaves. For effective control apply a preemergence herbicide containing isoxaben in April to control weeds before they germinate. Since this herbicide has no effect on emerged weeds, a postemergence herbicide containing 2,4-D, MCPP, and or dicamba should be applied for weeds that have already germinated.

·        Proper cultural practices will help limit summer annuals. ”

“Weeds that spread by stems such as GROUND IVY, THISTLES, OR FIELD BINDWEED, can be extremely difficult to control. Multiple  herbicide applications may be required due to the spreading nature of these weeds. Herbicides containing 2,4-D, MCPP, and dicamba can be effective in the fall. For particularly stubborn weeds, products containing triclopyr, fluroxypyer, or aminocyclopyrachlor can be used. If BINDWEED is a problem, a product containing Quinclorac (Drive) can be very effective. If these weeds are becoming a real nuisance you may consider hiring a professional to control these difficult weeds. ”

“While complete weed control in you lawn is never possible, practicing good turf cultural methods and applying herbicides when weed species are most susceptible you should be able to diminish the broadleaf weeds in you lawn.”

Resource: University of Nebraska-Lincoln Turfgrass Science Program Publication 2011b (