This is about a dozen egg shells ground to a fine meal. Egg shells contain calcium, a mineral that some vegetables need to thrive and inhibit disease. As I use eggs, I rinse the shells and set them aside until I have about a dozen. They dry over the course of several days and then are easy to pulverize.*
When I have enough, I mash them quickly with a potato masher, then run them through the food processor until the particles are fine. Some of the particles are as fine as dust, so I let them settle for a few minutes before taking off the lid.
Finally, I stir a tablespoon into the soil where I'm transplanting a seedling, along with whatever else I'm adding at the time. In the case of this batch of eggshell meal, I also added epsom salts, as I was transplanting tomato seedlings. Epsom salts are an available source of magnesium, a nutrient that tomato plants need along with the calcium.
It's free. It benefits my vegetable production. And it does something useful with the eggshells.
*Damp eggshells don't pulverize into a meal very easily. If using freshly rinsed egg shells, it's best to dry them in a warm oven on a baking sheet for about 30 minutes, like right after you take baking out of the oven, and the oven is still hot to warm.
