Some people have questions and fears related to using “treated lumber” for raised vegetable garden beds. We direct people to the following research studies and information sources to address their questions and concerns.
Penn State Extension: Environmental Soil Issue - "Garden Use of Treated Lumber." (download pdf)
Human Ecological Risk Assessment (journal): "Human Health Risk Evaluation of ACQ-Treated Wood." (download pdf)
Walter Reeves - The Georgia Gardener (blog post)- "Treated Wood - Safety of ACQ"
To summarize, the study published in Human Health Risk Evaluation above concludes (on page 20): “This risk evaluation included all chemical components of ACQ Type D that might be present on the surface of ACQ-treated wood. Overall, the results demonstrate that exposure to copper, DDA Carbonate, and MI/MCI from ACQ Type D from the surface of treated wood are not expected to be associated with any adverse effects to adults or children who might come into contact with this product.”
We began using treated lumber for raised garden beds because of its price, ease of use, ease of obtaining, and long life.
Some of the raised garden beds we now build provide 52 cubic feet (4 ft x 30 in x 8 in) of planting soil space for nearly the same price as the raised bed typically available at your local big box store that provides only 2 cubic feet (1 ft x 2 ft x 1 ft) of planting soil space.
It is worth noting that we have traditionally been against using treated lumber in our work because the landfill is the only disposal destination for it; that is, it is wasteful. As such, we advocate using used decking wood and other similarly sized used treated lumber - in place on new treated lumber - as a great, very cheap, source of wood to build a raised garden bed. This method utilizes a "waste" while also providing a garden growing space.
We would be happy to work with you to build a raised garden bed specific to your needs using either new or used "waste" treated lumber. Please contact us at email@example.com or 772-453-7494 to discuss your ideas.