Eliminating Lawn Burweed

Lawn Burweed

The extremely cold winter even slowed the weeds down a little.  However, as soon as it warmed up a little, they took off like gang-busters.  Then my phone started ringing with homeowners looking for control solutions. 

Depending on the weed species I might tell them to mow the weeds or wait until warm kills off the winter annuals.  One big exception to these two scenarios is if they have lawn burweed also known as spurweed.  This weed needs to be destroyed now before it flowers and produces those little, sharp, brown seeds with spurs. The simplest way to do this is with a timely application of a postemergent herbicide.

  A three-way combination herbicide may be used on bermudagrass, zoysiagrss, centipedegrass, or St. Augustinegrass. The active ingredients of a three-way herbicide often include the following broadleaf weed killers: 2,4-D, dicamba, and mecoprop (MCPP). Examples of a three-way herbicide are Ferti-lome Weed-Out Lawn Weed Killer with Trimec, Bayer Advanced Southern Weed Killer for Lawns, Spectracide Weed Stop Weed Killer for Lawns, Southern Ag Lawn Weed Killer with Trimec, and many others regional brands.  Ferti-Lome Weed Free Zone adds a fourth chemical, carfentrazone to broaden the spectrum of weed control.  Spectracide Weed Stop 2X for Lawns also adds a fouth chemical, sulfentrazone.

If the clumps have gotten large or the weather is too cool, two applications might be necessary.   Wait 10 – 14 days after the first application to make the second one.  Do not apply these herbicides around the drip-line of trees or in flowerbeds. Always follow label instructions and precautions.

Another piece of advice for effectively controlling lawn burweed is to apply an appropriate preemergent herbicide during the fall or late winter months.

Preventing Summer Annual Weeds in Your Lawn

Common lespedeza

As winter begins its transition into spring, we look to the beautiful, yellow blooms of yellow bells (Forsythia sp) to remind us to apply pre-emergent weed killer to the lawn

Well, mine is not blooming this year.  I cannot ever remember not seeing a yellow bell bloom in the spring, but apparently that last hard freeze killed most of the buds on my plant.

 I generally tell people to apply their chemicals by the calendar and not by when a plant blooms, so it is not too big a deal for me except I miss the bright, yellow flowers.

Anyhow, now is the time to apply pre-emergent weed killers to your lawn to control those pesky, summer annual weeds.  It is best to try to control them now so you will not have to call me later in the summer with a problem.  There are several good products from which to choose:

1. atrazine                        Image herbicide for St. Augustinegrass and Centipedegrass with Atrazine; Spectricide Weedstop for Lawns; Hi-Yield Atrazine Weed Killer

2. dithiopyr                        Sta-Green Crab Ex; Green Light Crabgrass Preventer; Vigoro Preemergent Crabgrass and Weed Preventer; Hi Yield Turf & Ornamental Weed & Grass Stopper

3. pendimethalin               Scott’s Halts Crabgrass Preventer

4. oryzalin                         Southern Ag. Surflan A.S.

5. isoxaben                       Portrait Broadleaf Weed Preventer

6. benefin + oryzalin          Green Light Amaze Grass and Weed Preventer; XL 2G

7. benefin + trifluralin         Hi-Yield Crabgrass Preventer; Southern Ag. Team 2 G

8. corn gluten meal            Concern All Natural Weed Preventer Plus; Nature’s Guide Corn Gluten Meal   

I often tell clients to buy any product that has ‘crabgrass killer’ in its name.  That makes it easy to remember when they go to purchase a product.  These products will control many other weeds beside crabgrass however.  The key to good control with any of these products is to apply them before a rain or to water the lawn within a week of application to move the chemical into the soil.

The corn gluten meal products are primarily for those who want an organic form of weed control.  It is primarily effective on crabgrass only.  Also, due to the high temperatures and high rainfall in the south, it will be less effective than the other products.

As for those ‘weed and feed’ products that are supposed to control weeds in your lawn and fertilize it at the same time, do not waste your money.  You need to be applying your weed control product now.  Your grass will not need any fertilizer for about two more months. 

Before you use any chemical, be sure to read and follow the instructions on the product label . . . even if you have to put on your glasses!