It’s officially winter in Texas! Warm one day and cold the next!  This time of year is challenging for gardeners because we worry about protecting plants from freezes, getting enough chill hours for our fruit trees, and trying to control winter weeds like henbit, dandelion, and wild carrot.  Unfortunately, it’s also time to think about preventing our warm season weeds like crabgrass, carpetweed, pigweed, and many others.

Mid-February is the time to put out pre-emergent weed killers if you have problems with weeds in your lawn. A pre-emergent herbicide will kill weeds before they begin actively growing.  You need to consider two important factors when you prepare to treat weeds.  What kinds of weeds do you have and when is the best time to treat them?

Broadleaf weeds have netted leaf veins in a variety of leaf shapes. An example of a broadleaf weed is henbit or ragweed.  We have a wide range of herbicides that will target just broadleaf plants.  A good pre-emergent herbicide for broadleaf weeds is isoxaben, commonly found in products like Gallery or Fertilome Broadleaf Control with Gallery.  This is a granular product that should be broadcast using a spreader and watered into the lawn.

Grassy weeds have parallel veins with long, slender leaf blades. Crabgrass and sandbur stickers are common grassy weeds.  You need a separate herbicide that will target grassy weeds.  Some good options for grassy-weed pre-emergents are prodiamine found in Barricade; pendimethalin found in Scott’s Halts Crabgrass Preventer, Pre-M and many others; or dithiopyr found in Bonide Crabgrass preventer.  These are also granular products that should be made in a separate application than your broadleaf herbicide.  Just think of how many extra steps you can get in while you work!  Gardening is a great fitness program.

Be sure to put out pre-emergent herbicides by mid-February. They don’t work if the weeds have already germinated and started growing.  Timing is very important.

One final note, many people like to double up on tasks and use a “weed and feed” product to treat weeds and fertilize the lawn at the same time. This sounds like a time-saving step, but we need to treat weeds now and it is much too early to fertilize.  Any fertilizer you put out now will be used by the winter weeds that are growing or will be wasted.  Wait until mid-April to fertilize when the grass is actively growing and needs nutrients.