Use concrete blocks for raised bed?

Asked April 21, 2020, 3:27 PM EDT

Hi! I bought some concrete blocks from home depot to build a raised bed and heard they may toxicate vegetables. This is how the blocks look https://www.homedepot.com/p/8-in-x-16-in-x-8-in-37-5-lbs-Concrete-Block-3306680000/202535901 Many thanks!

Washtenaw County Michigan

1 Response

Thank you for your question. Your concern is valid. The toxicity is primarily linked to the fly ash added to some concrete blocks. Home Depot should be able to find out whether fly ash is one of the raw materials. After looking into this it is obvious there is no consensus as to the perils of using concrete blocks for raised beds. Some It is suggested that if there are concerns that the blocks can be sealed to prevent leaching into the soil. A barrier of heavy plastic film could also work.
Check out the following links:
https://extension.uga.edu/publications/detail.html?number=C1027-5&title=Raised%20Bed%20Materials
https://extension.umd.edu/hgic/topics/materials-building-raised-beds
I hope this is helpful,