Untreated pine or Douglas fir (budget option)

Untreated pine and Douglas fir are the most affordable wood options, costing roughly 50-60% less than cedar. A 4x8-foot bed can be built for $40-80 in lumber. The trade-off is lifespan: expect 3-5 years in wet climates, up to 7 years in dry climates. This makes pine a good choice for renters, first-time gardeners testing the hobby, or anyone on a tight budget who plans to rebuild eventually. Douglas fir is slightly more durable than pine due to higher density. To maximize lifespan: use 2-inch thick boards (not 1-inch), keep soil from direct prolonged contact by lining interior walls with 6-mil plastic sheeting, and elevate the bed slightly on gravel. Some gardeners get 5+ years from pine by applying linseed oil or a food-safe sealant annually. Never use painted or stained lumber of unknown origin, as older paints may contain lead.