Save your eggshells & egg cartons as perfect containers for your seedlings!
Wash in hot water, and keep large darning needle by sink to punch drainage hole in bottom (it is easier to punch thru from the inside/out). Put back in carton until ready to plant.
Fill with potting soil and follow seed package directions.
Water with spray bottle and top with plastic wrap until germinated.
When seedlings are big enough to plant outside, just plant seedling in eggshell after slightly crushing the shell in your hand…there is no transplant shock and the eggshell provides calcium, a required nutrient.
If seed needs stratification, do not spray water until after cold treatment.
— Ann Ironside & Pam Sheldon