Raised Bed Materials: Treated Lumber, Plastic, or Untreated Wood?

Q: Should I avoid landscape timbers for vegetable beds? Are non-treated timbers available?

No need to use treated lumber if you prefer not to. Old CCA treatment phased out 2003–2006; current ACQ (alkaline copper quaternary) is less problematic. 2×6 framing works well.

Alternatives:

• Plastic lumber (Trex, Fiberon): No chemicals, but needs steel rebar reinforcement every 36 inches.
• Pressure-treated deck planks (5/4×6): My choice—reinforced with 18″ rebar every 4 feet.
• Untreated 2×6 or 2×8: Lasts ~3 years, easy to replace.

See Treated Wood – Safety of ACQ.

raised bed