But I've also heard that the plastic leaches chemicals into the ground and since this is a vegetable garden, I want to be as safe as possible. They are collected and sold to Trex for recycling, instead of going to a landfill to resist decomposition forever. But it saws, planes and nails as well or better than wood. Also, Trex sawdust is greasy and does not fly and cause sneezing or a potential flash-fire hazard like wood sawdust. Termites can't eat it and molds won't infiltrate it.
Nothing can soak in or leach out.
So it is ideal for raised beds. Trex will accept paint as well as wood. Left unfinished, as in a raised bed, it weathers to a light silvery gray, similar to cypress or cedar. Some say the critics' problem is less with consumer products than with private enterprise itself, and that they are the long-overdue death rattle of Karl Marx. Maybe so, but we need'em, right or wrong.