I have not tried this yet, but had been thinking about it after I noticed the wood rotting in my fir raised bed. Why not try some of the weed barrier landscaping material? I might suggest tyvek, but don't know about what it might leach/gas off into your planter mix.

Boiled linseed oil is the wood preservative of choice among organic gardeners. You can use it on the outside and the inside of planters.

Just curious: by "planter", do you mean a large square or rectangular "pot" (with sides AND bottom)?

A "raised garden bed" to most people means it has no "bottom" -- the soil just goes right down further into the ground.

Joe

Joe, thanks for the tip. You are right, our garden bed has no bottom.

I find boiled linseed oil does not want to penetrate the wood very well and I thin it with Turpentine. I apply as many coats as needed until it will no longer be absorbed. Al

I read that Turpentine is toxic. Is there any other organic oil/thinner which can be used to dilute boiled linseed oil?