In our last issue, one of the questioners in our Q&A section wondered about finding a food-safe, yet rot-resistant, wood choice for raised planter beds. Other readers had a few additional suggestions. – Editor
“George White asked about treating Hemlock to prevent rot. About 4,000 years ago, the Egyptians discovered that heat treating wood would make it impervious to rot and critters. I tried this process recently for another reason, but the heat treating does make the wood rot-resistant I used 400 degrees Fahrenheit for an hour and the wood turned dark uniformly. The wood does not get stronger or have other attributes, according to the experts. Now, how to get a large piece of wood to 400 degrees is a challenge. I don’t know how you would do that. The Egyptians used hot sand from an urn heated over a fire and spread on top of the wood which was in a shallow trench. Today, maybe gas or electric heaters in a temperature-controlled chamber. Using a toaster oven, I got birch to look like walnut. Linda (wife) was not happy about me using the family toaster oven, so I bought one at a thrift shop. Works well, but size is limited. Doesn’t work on some soft woods. Cedar, no. Pine, sometimes. Redwood, no. Douglas fir plywood, no — delaminates. Birch, alder, poplar, walnut, cherry, and oak darken nicely. Thought you might be interested.” – Bruce Adams
“There is one aspect of this subject that wasn’t even mentioned. By raising the ‘raised planter bed’ above ground, the life of the lumber involved in making the planters can be greatly extended. And since the individual involved was handicapped, this might be a better way to go. For more information on this method, visit my new friend Rich, at http://handihelp.net/ and take note how he “raised” his beds for easier access in his wheelchair. Note the construction uses pressure-treated lumber, but I would use it in the base only, providing no contact with it and the food crops. Plans are here. Seeing that he had some trouble maintaining a hard surface for his wheelchair and was using plain compressed stone-dust only, I dropped him an email and suggested a possible answer for him passed down to me over generations. It is now commonly referred to as “Soil-Cement”. After asking permission from me, he published my letter in its entirety here on the process. There are other pages with more information on this process on Rich’s site as well as in a Google search. I hope this will give George another option to consider. And as I am also handicapped, I hope to get some of Rich’s raised planter beds built before I get to the point of needing a wheelchair all the time, too. (I currently use a walker) Thank you for your time and excellent newsletter!” – Dennis (Denny) Marsh
“Geo. White could use black plastic between preserved wood and his soil. Best by far is to go another route – cinder block, retaining wall block, rock…” – Elaine Duff
