Usually applied in mid to late April prior to Crabgrass germination which occurs in our area around the first week of May depending on weather patterns.
Granular or liquid application.
Should be watered in within 7 days. The sooner the better.
Products used are generally of low toxicity.
Most often with a “caution” rating.
Crabgrass Pre-Emergent only last 12 weeks or so. Therefore timing of application is important. On lawns with a history of poor crabgrass control a second application should be made about six weeks after the first application.
100 % control of Crabgrass is rare and should not be expected.
Many factors are involved such as:
• Height of mowing. The higher the cut the better to crowd out weeds and better turf plant health overall.
• Extremes of weather can reduce control. Too much rain or over watering with your irrigation system can dilute and wash away the product prematurely. Hot dry weather and lack of any water and the product can volatize and evaporate away faster than normal.
• Insufficient organic matter in the upper soil profile. The product needs organic matter to cling to which enables it to stay in the top ½ inch to 1 inch of soil. At that level it is there and ready to work on Crabgrass seeds as they germinate. If the soil is too sandy the materials drop lower down in the soil profile and will not work properly.
