Raised Bed Material
I'm ready to build some raised beds for our vegetable garden. I need some ideas and opinions on materials to use. We want something that will endure the weather, soil moisture in the garden, and ground contact.
We will have four 4'x4' beds about 16-18" high.
Cheapest and in the thickest dimension (2") is treated lumber. I know this was determined to be a health hazard some years ago, but now they say it is environmentally safe. I'm skeptical but it would be perfect. Contaminated beans don't appeal however.
Cedar is attractive but I can only find 1" thick boards, which I feel may bend or buckle with the weight of the soil, even in 4' lengths. Moderately expensive.
Composite "lumber" also is only available in 5/4" thickness and is really costly. We used it a few years ago for a raised bed and had buckling problems with 8' lengths. A design flaw I guess, but still very expensive. And who knows if this stuff leaches anything into the soil.
What can you tell us about good and safe materials for our raised beds? Can you turn us to any place that has design ideas for building what ought to be simple rectangles?
We appreciate all your experience and any help you can give. Thanks.