crab grass preventative

Asked April 8, 2019, 6:18 PM EDT

When do you put down crab grass preventative in Minneapolis? When is it applied in southern Minnesota (along Interstate 90)?

Hennepin County Minnesota crabgrass preemergent pre emergent herbicide grassy lawn weeds

1 Response

Thank you for the question. Pre-emergent products for crabgrass control are applied when the soil temperature reaches 55-60 degrees which is about 2 weeks before the crabgrass seeds germinate for the year. Typically, in the Twin Cities this is around early to mid- May but it might be a bit earlier in southern MN. There is no hard and fast calendar date because weather varies each year. Soil temperatures can be checked with a soil thermometer or even a kitchen meat thermometer. Each yard and even separate areas within your yard might obtain these temperatures at different times, especially along sidewalks or driveways. Applying herbicide across the entire yard may not be necessary, instead target areas where crabgrass has been an issue in the past. Overall this will result in the use of less chemicals and cost savings. Learn more here: https://local.extension.umn.edu/local/article/lawn-fertilizer-and-herbicide-best-practices

Thank you for contacting Extension.