Alive Structures uses recycled shredded paper, recycled Styrofoam, and combines it with cement to make their planters.
The design each one with succulents, saxifrages, and alpine flowers. Gorgeous! In addition they also do green roofs.
If you can't get your roof done, the planters are sold online, or will be available this spring at The Brooklyn Flea, The Park Slope Community Market, and SustainableNYC.