Don’t throw egg cartons 

Egg cartons make great growing containers for seedlings. The egg carton’s moisture and warmth and the rigid structure help the seedling roots develop correctly. There are a few vital things to have in mind when growing seedlings in egg cartons. Make sure the egg carton is clean and free of any debris. This will help to promote healthy growth. Choose a container that is roomy enough for the seedling’s root system but not so massive that it becomes crowded. Water the seedlings regularly with a garden hose or mist them with a spray bottle. Let the soil dry between waterings.