Ideal Garden Box Meterials
Hello, My name is Zannon Miller. Thanks for taking the time to answer the many questions I am certain you have been receiving; we appreciate your work. I am looking to start a handful of garden boxes. they will be mostly for fruits and vegetables, with some flowers. I am excited to build the boxes, but I have had difficulty knowing what materials to use. I am attracted to the look of the wood/metal boxes that have been popular recently, but I want to be certain that the galvanized metals will not leach harmful particles into the soil and our food. I have heard that redwood and black locust are costly but the best bet for boxes... is this true in your experience? The gardener at this website: http://blueberryhillcrafting.com/2013/04/24/how-to-galvanized-garden-beds/ built beautiful beds. I would love to build something to match, and it seems that using pressure treated wood in the case of these boxes would not be a danger because only the metal is touching the soil. As long as the metal is safe, the crops should seemingly be too. In addition, if you have any favorite articles on garden box building or maintaining, I would be very grateful to take a look. Thank you! Zannon Miller Portland, Or
Multnomah County Oregon
Thank you for your question about raised garden beds. As you may have noted in the OSU Extension publication “Raised bed gardening” a variety of materials can be used for building raised beds. https://catalog.extension.oregonstate.edu/fs270.
Oregon State University has done research on the new type of pressure treated lumber and found it is safe for use for vegetable gardening. The original pressure treated lumber used arsenic as one of the components for pressure treating. The new (since 2004) pressure treatment Alkaline Copper Quaternary (ACQ) is safe for use in raised beds. Here is the link to an OSU publication that discusses ACQ pressure treated lumber in raised beds. http://extension.oregonstate.edu/question-of-the-week/raised-bed-lumber-pressure-treated-safe.
As you noted, redwood and cedar are good choices for raised beds, however, are more expensive. Untreated pine is an option, though as you stated, will not last as long. You may find the following publication on materials for building raised beds of interest: https://extension.umd.edu/hgic/topics/materials-building-raised-beds