Is Pressure-Treated Lumber Safe for Gardens?

History

• The concern over using pressure-treated lumber in garden beds arose concerning a specific treatment product, chromated copper arsenate, or CCA. Heavy metals from CCA could potentially leach into garden soil and into vegetable plants, possibly causing hazardous levels of heavy metals in the vegetables. In 2003, however, the lumber industry discontinued the use of CCA-treated lumber.

Copper-Treated Wood

• After the discontinuation of CCA, lumber treatments relied more heavily on copper, a natural fungicide. Copper-based wood treatments will help prevent decay from fungus and are safe to use in the garden.

Creosote-Treated Wood

• While creosote poses no health risks to you or your family, creosote -- typically used to treat railroad ties -- can kill your plants. Old railroad ties are safe, but if the ties ooze black liquid or have a strong odor, avoid their use.