landscape timbers for raised beds
Location: Hallsville, Te
Question: Is it ok to build raised garden beds out of treated landscape timbers for my vegetable garden? I did not know if the chemical in the treated timbers could be unhealthy.
Answer: There\'s still a lot of controversy about using treated wood for vegetable gardens. There was a time when pressure treated lumber contained arsenic (CCA) and was not considered safe for use in raised vegetable gardens because the arsenic leached out into the soil. The newest method for treating wood is Micronized Copper Quaternary (MCQ). It is chemically different than the old CCA treatments. It is made of tiny (micro) particles of copper. These particles are forced into the wood cells or pores during the pressure cycle. Once in, they stay in, also forming a barrier keeping in the quaternary. The leaching of chemicals out of MCQ is practically non-existent and using the treated lumber for a vegetable bed is safe because the chemicals do not leach out into the soil. If you can find MCQ treated lumber, you can use it in your garden. If not, choose a wood that is naturally rot resistant. Redwood, cedar and cypress are good choices. Pine and hemlock are poor choices because they are soft and prone to rot. Or, you can use concrete blocks or interlocking landscape stones for your raised beds. Best wishes with your garden!