What Can I Use to Kill Tall Grass in My Yard?

Annual and Perennial Identification

• Annual grassy weeds germinate in the spring. These weeds produce shorter root systems than perennial weeds. Crab grass is an example of a common annual grassy weed. Gardeners may use both cultural and chemical control methods to kill annual grassy weeds. Perennial grassy weeds are more difficult to kill, because there are no selective herbicides available to use on this weed type. Gardeners must use cultural methods and broad-spectrum herbicide on tall perennial weeds.

Digging

• You can dig up both annual and perennial weeds out of the yard. If you decide to hand pull these weeds, allow the weeds to grow tall without mowing them to easily pull them out. Wet the soil or dig up weeds in the morning when the soil is moist. Push your shovel to a depth of at least 6 inches to remove their root systems. Leaving root systems in the ground results in them producing more grass blades.

Selective Herbicide

• You can use selective herbicides on annual weeds without harming your own turf grass. Avoid mowing your tall grass two days before and after applying the herbicide. The more surface area on the plant the more herbicide is absorbed. Use a selective herbicide on your annual weeds that indicates it can be used on your grass. It is important to note that mature tall annual weeds are difficult to kill with herbicide. Gardeners may need to repeat the herbicide application or use broad-spectrum herbicide.

Broad-Spectrum Herbicide

• Broad-spectrum herbicide kills anything that comes in contact with the spray. After using a broad-spectrum herbicide to remove tall weeds, gardeners must reseed these bare spots in the lawn. Other weed types will take over bare spots left in the lawn. Spray your broad-spectrum herbicide when you have two days of dry weather. Turn off your irrigation system before spraying. Wait five to 14 days to replant your former weedy areas.