Using cardboard to kill grass - Ask Extension
To enlarge my flower beds that are next to grass, I read that you can lay cardboard down over the grass, adding grass clippings and compost on top and...
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Using cardboard to kill grass #853913
Asked October 24, 2023, 1:16 PM EDT
To enlarge my flower beds that are next to grass, I read that you can lay cardboard down over the grass, adding grass clippings and compost on top and let it sit thru the winter. In the spring you till it to create a new bed.
My question is, are there chemicals in the cardboard that you don’t want in the soil?
Kalamazoo County Michigan
Expert Response
Hello,
I was able to find a great article from the University of Illinois Extention on landscape screening that addresses all types of materials, including cardboard. I think you will find it helpful. https://extension.illinois.edu/blogs/good-growing/2021-06-25-disadvantages-landscape-fabric
A couple of thoughts - I do use cardboard to cover areas I want to clear of grass and weeds. I may treat with glysophate first and then cover for the winter or longer. Glysophate does not stay active in the soil, so there is not residual effect. It only kills what it touches. It's probably too late to use glyphosate now because it should be applied when the weather is warmer.
I don't use cardboard as a weed barrier in the garden for the reasons stated in the article. I usually remove the cardboard and use other materials such a newspaper, which works very well.
Finally, if you do use cardboard over grass, be sure to cut the grass very low. If you cover the cardboard, I would use compost and shredded leaves.
If you have more questions or need additional information, please contact us again.
I was able to find a great article from the University of Illinois Extention on landscape screening that addresses all types of materials, including cardboard. I think you will find it helpful. https://extension.illinois.edu/blogs/good-growing/2021-06-25-disadvantages-landscape-fabric
A couple of thoughts - I do use cardboard to cover areas I want to clear of grass and weeds. I may treat with glysophate first and then cover for the winter or longer. Glysophate does not stay active in the soil, so there is not residual effect. It only kills what it touches. It's probably too late to use glyphosate now because it should be applied when the weather is warmer.
I don't use cardboard as a weed barrier in the garden for the reasons stated in the article. I usually remove the cardboard and use other materials such a newspaper, which works very well.
Finally, if you do use cardboard over grass, be sure to cut the grass very low. If you cover the cardboard, I would use compost and shredded leaves.
If you have more questions or need additional information, please contact us again.
