The thought I have is a floating island made of natural materials will probably deteriorate every year and have to be rebuilt so as to keep floating. A much easier and simpler floating island take of my foam rock island would be a 4x8 foot sheet of closed building foam with a foam ridge liquid nail glued around the edges to hold the dirt in. Small 1 inch holes drilled randomly over the panel and packed with moss or even dirt which I believed would siphon water into the growing medium without ropes as I used. It would float year after year without water logging and having to be rebuilt, and the outside edges could be heated with a heat gun or torch to crisps it into a tough skin.
