clean, empty gallon jug (a plastic milk jug works fine)
wide-mouth jar or container with lid
10eggshells (or more)
1 gallonwater(rainwater, distilled, or filtered water is best)
Rinse your eggshells with cool water. It's fine if they still have some egg white residue and/or membrane.
Place the eggshells in a single layer on a baking sheet, and dry in the oven for about 2 hours on its lowest setting (usually around 180°F / 85°C). There's no need to preheat the oven.
Remove eggshells from oven and allow to cool.
Break eggshells into smaller pieces with your fingers. Using a coffee mill, crush eggshells to a fine powder. Or, use a rolling pin on a wooden cutting board to pulverize the shells.
Place the crushed eggshells in the wide-mouth container (you can use this to store any eggshell powder you don't use right away).
Scoop out 2 TBS eggshell powder per gallon of water you plan to use for your plants, and place it in the bowl.
Add the same amount of white vinegar to the crushed shells. Stir the mixture with a non-metal utensil to allow the vinegar and eggshells to react—you'll notice some bubbling.
Let the mixture sit for a minute or two, then give it another good stir. Let the mixture sit for about an hour to allow the vinegar and eggshell to complete the reaction.
Put 4 TBS of the eggshell/vinegar solution into a spouted measuring cup, and swirl in some water to make it easier to pour. Pour the solution into the gallon jug, then fill almost to the top with water. Put the lid back on the jug and shake well.
Fill your watering can from your gallon jug, and water your plants with your calcium-rich eggshell fertilizer!
Water-Soluble Calcium Eggshell Fertilizer https://leafylittlehome.com/eggshell-fertilizer/ January 11, 2021