Crabgrass prevention, fertilizing and over seeding. - Ask Extension
Hi,
I live in Ramsey. I would like to over seed, prevent crabgrass and fertilize this spring. I was thinking I could over seed and then apply a fer...
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Crabgrass prevention, fertilizing and over seeding. #926472
Asked March 21, 2026, 8:32 PM EDT
Hi,
I live in Ramsey. I would like to over seed, prevent crabgrass and fertilize this spring. I was thinking I could over seed and then apply a fertilizer/crabgrass preventer. Could you provide recommendations for 1) timing and 2) fertilizer/crabgrass preventer brand or product type?
Thank you!
Anoka County Minnesota
Expert Response
It's possible to do what you have in mind, but the timing of seeding, fertilizing and crabgrass preventer application must be carefully considered.
According to experts at Iowa Sate University, "Preemergence herbicides, such as benefin, bensulide, dithiopyr, pendimethalin and prodiamine, prevent the germination of crabgrass seeds in spring. They also prevent the germination of turfgrass seeds. If you intend to sow grass seed in spring, the only preemergence herbicides that can be used are siduron (Tupersan) and mesotrione. Siduron and mesotrione effectively control crabgrass without affecting the germination of turfgrass seeds. Siduron and mesotrione are found in starter lawn fertilizer/weed preventer products at garden centers and other retailers."
Go here for more information that addresses your question:
https://kansashealthyyards.org/component/allvideoshare/video/weed-control-when-planting-grass-seed
https://turf.umn.edu/news/spring-preemergent-applications-crabgrass
According to experts at Iowa Sate University, "Preemergence herbicides, such as benefin, bensulide, dithiopyr, pendimethalin and prodiamine, prevent the germination of crabgrass seeds in spring. They also prevent the germination of turfgrass seeds. If you intend to sow grass seed in spring, the only preemergence herbicides that can be used are siduron (Tupersan) and mesotrione. Siduron and mesotrione effectively control crabgrass without affecting the germination of turfgrass seeds. Siduron and mesotrione are found in starter lawn fertilizer/weed preventer products at garden centers and other retailers."
Go here for more information that addresses your question:
https://kansashealthyyards.org/component/allvideoshare/video/weed-control-when-planting-grass-seed
https://turf.umn.edu/news/spring-preemergent-applications-crabgrass
