Not sure if this belongs in this area because its sort of a landscaping idea.. I want to make a patio.. It will have wood 2x4s to make a sort of checkered pattern.. Inside the squares will either be concrete or pavers.. Now, I want to use the composite wood but its very expensive per board, and I'm wanting to do a good sized area.. But it will also be next to and around my vegetable beds.. Would treated wood be ok around the vegetable beds, as long as the vegetable beds are made of something non treated? I can't use non treated wood for the pattern because my yard gets very wet in the summer and it would not last very long.. I just don't know if contaminants from the treated wood would leach up into the vegetable beds.. Would stuff like that leach up, against gravity?