When to cut grass after allowing the lawn to go to seed. - Ask Extension
How can I tell if the grass head has seeds that are mature enough to mow and those seed heads will germinate?
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When to cut grass after allowing the lawn to go to seed. #929804
Asked April 27, 2026, 3:18 PM EDT
How can I tell if the grass head has seeds that are mature enough to mow and those seed heads will germinate?
Champaign County Ohio
Expert Response
Hi William.
This in an interesting question.
Here are three sources that show you what to look for in determining ripeness.
I've found an article from the US Natural Resource Conservation Center where it says that "in general the period between bloom and seed maturity is about 4 weeks. Cool moist weather may lengthen the interval while hot dry weather may shorten it." It has diagrams to show how to tell when the seeds are ready. Read more here https://www.nrcs.usda.gov/plantmaterials/txpmcbr6492.pdf
A second source, while not backed up by research but easy to follow is this article
https://yourcoolhomehq.com/when-is-grass-seed-ripe/
You're checking for ripeness by gently squeezing the seeds. If ripe, they should have a slight give but not mushy and the color is more brown.
The third source is this article
When Is Grass Seed Ready To Harvest - GardenerBible
lastly, a question for you. Are you willing to let the grass grow long enough for the seed heads to mature before mowing?
There are many articles about harvesting grass seeds but I think that you want to wait until the seeds are ready, then mow, so that they will germinate in place?
This in an interesting question.
Here are three sources that show you what to look for in determining ripeness.
I've found an article from the US Natural Resource Conservation Center where it says that "in general the period between bloom and seed maturity is about 4 weeks. Cool moist weather may lengthen the interval while hot dry weather may shorten it." It has diagrams to show how to tell when the seeds are ready. Read more here https://www.nrcs.usda.gov/plantmaterials/txpmcbr6492.pdf
A second source, while not backed up by research but easy to follow is this article
https://yourcoolhomehq.com/when-is-grass-seed-ripe/
You're checking for ripeness by gently squeezing the seeds. If ripe, they should have a slight give but not mushy and the color is more brown.
The third source is this article
When Is Grass Seed Ready To Harvest - GardenerBible
lastly, a question for you. Are you willing to let the grass grow long enough for the seed heads to mature before mowing?
There are many articles about harvesting grass seeds but I think that you want to wait until the seeds are ready, then mow, so that they will germinate in place?
