How to Identify & Control Weeds in Oklahoma

The best way to keep weeds out of your lawn is to keep your lawn thick and healthy from proper mowing, watering, and fertilizing.  With that said, nobody wants weeds in their lawn.  However, as one man’s junk is another man’s treasure, so it is with weeds.


green grass

Poa annua in your Bermuda lawn?  Terrible stuff!  But, oddly enough, poa annua is used on golf courses.


Nutsedge driving you nuts?  Nutsedge is listed as a “noxious weed” by the Federal government and is a great threat to agriculture.  But it’s been around since 4000 B.C. and was one of the first domesticated crops in Egypt – the nuts were eaten, used as an ingredient in drinks, made into perfume and fibers, and they still are in some countries.


Basically, a weed is defined as something growing where you don’t want it to grow.


Below are the basic types of weed control.


  • Pre-emergent weed control prevents certain weeds from germinating (before the weed emerges.)
  • Post-emergent weed control kills the weed after it comes up in your lawn (after the weed emerges.)
  • Selective weed control refers to a material that affects a certain kind of weed only.
  • Non-selective weed control will kill almost anything you spray it on.


Here are the different types of weeds.


  • Broadleaf weeds spring up in the early spring and again in early fall, and sometimes throughout the summer.  Dandelions (yellow flower,) henbit (purple flower,) plantain, oxalis, clover, buttonweed – all are classified as broadleaf weeds.  Most of the common broadleaf weeds are relatively easy to kill with a post-emergent weed control.  There is no pre-emergent for most broadleaf weeds.
  • Grassy weeds can be very difficult to control and are the most persistent.  Why?  Because they’re grass, the same stuff that’s in your lawn.  We have pre-emergents for some grassy weeds, but not all. 
  • Sedges are probably the hardest weeds to control.  Nutsedge (also called nutgrass or water grass) is a perennial sedge, not a grassy weed.  Even when you burn out or smother the foliage with a weed control product designed for sedges, you never really eliminate the weed, and you can expect future outbreaks.


For more info on a particular weed, please refer to the list of weeds on the right.  (More pages on weed info on the way!)