Is cardboard for new native plant garden acceptable? - Ask Extension
For a no till solution, i am interested in using cardboard as a base, but I have read suggestions that no cardboard is completely safe. It will likely...
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Is cardboard for new native plant garden acceptable? #851588
Asked September 28, 2023, 10:15 PM EDT
For a no till solution, i am interested in using cardboard as a base, but I have read suggestions that no cardboard is completely safe. It will likely contain some dye or plastic that is hard to detect and not compostable. It's this true? Should i avoid using cardboard and seek a different method?
St. Mary's County Maryland
Expert Response
Hi- plain cardboard (unwaxed, taping and plastic labels removed) is an effective way to create a no-till bed. One layer of cardboard is sufficient.
There is research showing that cardboard mulches reduce the air exchange between the soil and atmosphere. This effect disappears once the cardboard is fully decomposed (probably less than one year in a high organic matter soil). Also, this effect is less of a concern in no-till beds less than 5-ft. wide because air will infiltrate from the sides of the bed.
There is new research showing that cardboard (at least in this one study) contains PFAS so there is a risk that if land-applied, it could increase PFAS levels in the soil and plant tissues. It appears that PFAS are most likely found in cardboard used in food packaging. We can't find information on the prevalence of PFAS in cardboard boxes used for shipping.
Wood chips are a good alternative to cardboard. Arborists will dump them at your house for free and an 8-inch layer will kill vegetation. You then move the chips round to install your plants.
Jon
There is research showing that cardboard mulches reduce the air exchange between the soil and atmosphere. This effect disappears once the cardboard is fully decomposed (probably less than one year in a high organic matter soil). Also, this effect is less of a concern in no-till beds less than 5-ft. wide because air will infiltrate from the sides of the bed.
There is new research showing that cardboard (at least in this one study) contains PFAS so there is a risk that if land-applied, it could increase PFAS levels in the soil and plant tissues. It appears that PFAS are most likely found in cardboard used in food packaging. We can't find information on the prevalence of PFAS in cardboard boxes used for shipping.
Wood chips are a good alternative to cardboard. Arborists will dump them at your house for free and an 8-inch layer will kill vegetation. You then move the chips round to install your plants.
Jon
Thanks for the response! It seems safer to avoid cardboard if possible, so I'm very interested in the wood chip approach. "Arborists will dump them at your house for free" - Do you have any guidance on how to find someone in the area that might do this? I was googling a bit and it wasn't entirely clear if you were referring to a business in the area or something else?
Hi- yes, contact businesses like tree removal companies and arborists. You can tell them exactly where you want the fresh chips dumped and approximately how many cubic yards you want.
Jon
Jon
