What is the best wood for raised garden beds?
There are only 3 types of wood that are suitable for raised garden beds and those are cedar, cypress and redwood. Other woods will rot quickly or get infested with insects like termites.
Cedar, cypress and redwood contain a chemical that termites and other insects do not like and they will avoid it.
Cedar, cypress and redwood raised garden beds will last 15-20 years if the climate is dry. It the climate is very wet then they may only last 8-10 years.
Never use pressure treated lumber for a raised garden bed. Pressure treated lumber has chemicals embedded into the wood to preserve it. You don’t want these chemicals getting into things that you are going to eat.
Never paint or seal lumber for a raised garden bed. Again whatever you paint on the wood will get into the garden soil and eventually into the plants. Do you want paints or sealants in your food?