Q. Hi Peter, I’d like to put a border around my approximately 40’X 40′ vegetable garden. Railroad ties would work nicely but I’m concerned about them leaching toxic chemicals into the soil and thereby ending up on my dinner table cleverly disguised as my awesome Super-Jubilee corn or Brandywine tomatoes. Are R/R ties a no-no around the garden? What would you suggest? Thanks Again, Henry Raynor – Puyallup, WA
A. Growing veggies in raised beds is a great idea. Raised beds generally warm up and dry out quicker in the spring, which means you can get a jump-start on those early crops. Also most gardeners do not walk in the raised beds, which means the soil is not damaged by compaction. You are very wise to be concerned about what you use to make the raised beds. Many gardeners that build raised beds may be tempted to used pressure treated wood. This makes sense from the standpoint of longevity of the wood. Treatment of wood with chemicals like creosote or chromated copper arsenate [CCA] slows down rotting of wood from soil microorganisms and insects like termites. Unfortunately when used near vegetable gardens is that as you suspect there can be leaching of these chemicals which can find their way into your vegetables and then inside you. Advocates of CCA pressure treated wood would tell you that the risk of contamination is low. So it is a risk benefit situation and everyone has to decide what he or she is comfortable with. The EPA maintains that treated lumber should only be used for outdoor structures. My sentiment is why take the risk when there are other options. I simply used untreated wood on my beds knowing I will have to replace them in 3-5 years. If you want longer lasting raised beds you could invest in naturally rot resistant woods like redwood or cedar. There is also plastic lumber made from recycled plastic which is UV protected. Unfortunately in the timber rich PNW plastic lumber has not, in my experience, been easy to find.