Egg carton-like trays of red, green and brown sedum perennials made the lawn look as if it rolled out of the house, up the wall and onto the roof.

FORBES: 8 Homes With Living Roofs

Washing not only warms up the egg, which then cools slowly in the carton, but also removes the natural protective film on the shell, opening the door to contamination from the washing water.

ECONOMIST: Food safety