Perfect on a flat roof. As the cells are pretty small water often. First couple of days bring them in at night, last two, leave them outside. As we've established everywhere is the best option. Fruit or tropical plants enjoy full exposure, as opposed to strawberries, wild garlic or lettuces and other greens who do better next to or beneath other plants.
Contaminated land can host flowers, non eatables, and fruit trees.
The toxins will be contained within the wood, and the fruit won't be affected. See the soil section for more details on how to create better environments. . Bag up roots of trees, keep exposure to the air as low as possible. Cellotape it alltogether for transportation. .