Take steps now for better spring lawn
By Wayne Morse
Extension Agent
Now is the time of year that it seems like everyone is talking about weeds! The winter weeds are actively growing and being a nuisance, and we need to start thinking about preventing warm-season weeds.
If you have problems with weeds actively growing in your yard now, those are cool-season weeds that started growing last fall and are now starting to actively grow. You can control them by hand-pulling, mowing, or using a post-emergent herbicide. You can purchase herbicide products in a ready-to-go spray bottle or mix up concentrated product in a small sprayer. Use the herbicide to spot-treat weedy areas of your lawn. Remember to read the label and follow the instructions for how much herbicide to use and the best time to spray. Weeds get tougher to kill when they get bigger, so take action sooner rather than later.
Early to mid-February is a good time to put out pre-emergent weedkiller for warm-season weeds that will be a problem later this spring and summer. Pre-emergent herbicides are generally the most effective option for controlling challenging weeds like crabgrass and annual bluegrass. Pre-emergent herbicides can be a safer option around your established landscape plants compared to some post-emergent products.
Timing is everything for pre-emergent herbicide applications, and it can be tricky to nail down the right time based on the environmental conditions. You can use soil temperature to plan your timing because soil temperature plays a critical role in weed seed germination. Plan your spring pre-emergent application when soil temperatures are around 55 degrees Fahrenheit for several days. Use a soil thermometer, or borrow the meat thermometer from the kitchen, and measure the soil temperature of the top one inch of soil.
Most local nurseries and big-box stores have pre-emergents for sale already. To control grassy weeds, look for products that contain the active ingredients dithiopyr, oryzalin, pendimethalin, or prodiamine. To control broadleaf weeds, look for active ingredient isoxaben. You might have to take your magnifying lens to read the product labels, but you can find these active ingredients in several different products. Always follow the label for application rates, timing, and PPE.
Aggie Turf has a great publication about selecting the right herbicide for your lawn: A Homeowner’s Guide to Herbicide Selection for Warm-Season Turfgrass Lawns.