Start seedlings in an egg shell and, when ready, plant the entire thing. The egg shells will naturally compost providing your plants with valuable nutrients.
Unless you’re a chef or an Olympic athlete who eats twelve egg whites for breakfast, it’s not practical to start a whole season of vegetable seedlings in eggshells. But, if you just want to start a few herbs or flowers indoors, this is a great concept. An egg carton fits perfectly on a windowsill, and the eggshell and even the carton will compost.