Pre emergent crabgrass on Clover lawn - Ask Extension
Hello,
Last year I had a bad spurge & crabgrass problem. I weeded the best i could at the end of the season & seeded with micro clover in ear...
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Pre emergent crabgrass on Clover lawn #926838
Asked March 26, 2026, 4:24 PM EDT
Hello,
Last year I had a bad spurge & crabgrass problem. I weeded the best i could at the end of the season & seeded with micro clover in early fall on the spots that needed covering.
I'm very tempted to use a pre emergent crab grass preventative & just avoid the areas I seeded and then in may seed the whole lawn again.
I've read so many conflicting things & the ultimate goal is to have clover take over but I need these other weeds under control & I think they're beyond high mowing.
Thanks!
Wayne County Michigan
Expert Response
Thank you for your question. Spring crabgrass control is achieved by applying a crabgrass pre-emergent. Control timing is best determined by using GDD Tracker (GDD Tracker) which tracks the cumulative heat exposure that warms soil and entices buds to open. More info in the following links:
GDD Tracking-Spring Crabgrass Prevention-MSU
Common Questions-Crabgrass & Pre-Emergent-Purdue
Crabgrass Control-UMn
Today GDD Tracker shows we are right at the beginning of the optimum time to apply pre-emergent which should last a week or longer. You should bookmark the GDD website for future use and can even sign up for alerts. The micro clover you seeded 'early last fall' should have germinated before winter but winter survival is questionable. I’d apply the pre-emergent now and then seed microclover later this spring after stirring the soil.
If you have thin spots in your lawn I would recommend doing a soil test to determine the soil fertility this spring. Knowing the type and fertility (pH, macro-nutrient levels, CEC, etc.) of your soil is the starting point to establishing & maintaining a strong/thick turf that can resist diseases, weeds, moss and insects/grubs and look great without wasting material or $. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer Soil test results will identify any fertility concerns that you can work to correct to improve turf health (it’s a well spent $26). Your report will provide recommendations to correct any deficiencies found, fertilizer type and a fertilization schedule (rate and timing) based on your preferred maintenance level (high, moderate or low).
Whiteclover is traditionally planted in ornamental lawns and grows in U.S. Department of Agriculture plant hardiness zones 3 to 11. "Dutch" or "New Zealand" white clover are the best varieties for lawns because they are low-growing and blend well with lawn grasses. Fescue varieties of turf grass are the most compatible with white clover as they need the least amount of fertilizer. Micro clover has it's good and bad points. It plays nicely in turf, especially turf-type tall fescue. But it is not hardy in hot, dry summers (when turf goes dormant) or cold winters and will need to be reseeded more frequently. Both clovers are nitrogen fixing which means they don't need to be fertilized like turf does and attract pollinators. You may still need to fertilize the lawn some. I do not have any info on the water needs of either clover. Links to more information:
Lawns & Microclover-UMaryland - pros & cons of microclover, open the pdf at the end of the article too.
Microclover info-Il
Here is some info on spurge and its control:
https://extension.psu.edu/lawn-and-turfgrass-weeds-spotted-spurge-chamaesyce-maculata-l
https://www.canr.msu.edu/nursery/uploads/files/Spotted-Spurge-E3461_FINAL-AA_2021-08-26.pdf
I hope this helps.
GDD Tracking-Spring Crabgrass Prevention-MSU
Common Questions-Crabgrass & Pre-Emergent-Purdue
Crabgrass Control-UMn
Today GDD Tracker shows we are right at the beginning of the optimum time to apply pre-emergent which should last a week or longer. You should bookmark the GDD website for future use and can even sign up for alerts. The micro clover you seeded 'early last fall' should have germinated before winter but winter survival is questionable. I’d apply the pre-emergent now and then seed microclover later this spring after stirring the soil.
If you have thin spots in your lawn I would recommend doing a soil test to determine the soil fertility this spring. Knowing the type and fertility (pH, macro-nutrient levels, CEC, etc.) of your soil is the starting point to establishing & maintaining a strong/thick turf that can resist diseases, weeds, moss and insects/grubs and look great without wasting material or $. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer Soil test results will identify any fertility concerns that you can work to correct to improve turf health (it’s a well spent $26). Your report will provide recommendations to correct any deficiencies found, fertilizer type and a fertilization schedule (rate and timing) based on your preferred maintenance level (high, moderate or low).
Whiteclover is traditionally planted in ornamental lawns and grows in U.S. Department of Agriculture plant hardiness zones 3 to 11. "Dutch" or "New Zealand" white clover are the best varieties for lawns because they are low-growing and blend well with lawn grasses. Fescue varieties of turf grass are the most compatible with white clover as they need the least amount of fertilizer. Micro clover has it's good and bad points. It plays nicely in turf, especially turf-type tall fescue. But it is not hardy in hot, dry summers (when turf goes dormant) or cold winters and will need to be reseeded more frequently. Both clovers are nitrogen fixing which means they don't need to be fertilized like turf does and attract pollinators. You may still need to fertilize the lawn some. I do not have any info on the water needs of either clover. Links to more information:
Lawns & Microclover-UMaryland - pros & cons of microclover, open the pdf at the end of the article too.
Microclover info-Il
Here is some info on spurge and its control:
https://extension.psu.edu/lawn-and-turfgrass-weeds-spotted-spurge-chamaesyce-maculata-l
https://www.canr.msu.edu/nursery/uploads/files/Spotted-Spurge-E3461_FINAL-AA_2021-08-26.pdf
I hope this helps.
