Treating or Painting Grow-Box Lumber

Q.  I am worried about using treated lumber to make my Grow-Boxes because of warnings about harmful materials in store-bought treated lumber.  What should I use?

A.  One alternative is to paint them with a good exterior paint.  The Grow-Boxes in Dr. Mittleider’s back-yard garden have been there for 25 years, with only occasional re-painting.
A second alternative is to make your own wood treatment.  The following comes from an article in a recent Organic Gardening magazine.
  • “Melt 1 ounce of parrafin wax in a double boiler (DO NOT heat over a direct flame).  [That’s a great way to start a fire]
  • Off to the side, carefully place slightly less than a gallon of solvent (mineral spirits, paint thinner or turpentine at room temperature) in a bucket, then slowly pour in the melted parrafin, stirring vigorously.
  • Add 3 cups exterior varnish or 1.5 cups boiled linseed oil to the mix, stirring until the ingredients are blended. When it cools, you can dip your lumber into this mixture or brush it onto the wood.”

    This should give you several years’ extended life for your Grow-Boxes.