Eggshell Powder as a nutrient: All plants need calcium, but some have a higher calcium need than others. Tomatoes, lettuce, peppers and the cabbage family (cabbage, broccoli, cauliflower, brussels sprouts) are some of the high calcium need veggies. When I plant these veggies I always add a large handful of egg shell powder into the hole and mix it in with the soil before I put the seedling in.
Eggshell Powder as a pest deterrent: After you have spent lots of time preparing your garden and planting your seedlings the last thing you want is to have the seedlings destroyed by slugs and beetles. Putting a ring of your eggshell powder around the base of your seedlings makes a physical barrier for slugs and beetles. The eggshells are like crushed glass to them and will stop them from getting to your plants. Just remember that you will need to reapply the eggshell ring after it rains and the rain will wash it away or cause it to sink into the soil.
How to make Eggshell Powder: I don’t know about you, but my family eats a lot of eggs. I keep a bowl above the sink and whenever we use eggs the shells go into the bowl. I do not clean the shells, but I just check that there is not a lot of egg stuck to the shells. Some people then dry the shells out in a low oven or food dehydrator. Personally, I just leave them in the bowl on the counter for a few days until they are dry. I then crush them up and put the in my Magic Bullet grinder and grind it into a powder. If you do not have a Magic Bullet, any coffee grinder or spice grinder will work. I then store the eggshell powder in a tightly sealed jar until I am ready to use it.