Rick Frame Polycarbonate and fiberglass might not be a good choice for edible plants -- Polycarbonate is plasticized with Bisphenol-A and fiberglass is made with epoxy resins, meaning that toxic chemicals can be leached from the container into the plants, and into your food supply.

Steve Masley Consulting and Design Plastics leach very little into soils, unless they're strongly acidic (or alkaline)--too acidic or alkaline to grow vegetables. Most of what does leach is flushed out when water runs down the sides of the pot. And then there's the matter of root uptake of toxins. While some plants to concentrate toxic metals--ferns, for instance, concentrate lead--there's very little evidence they take up more complex molecules like Bisphenol-A or epoxy resins.