Breaking the Egg Shell Myth

You've probably heard it before. To add calcium to your soil, put some crushed up egg shells in it!

I'm sorry to be a bummer, but that won't work.

You see, the calcium in egg shells is in the form of calcium carbonate, which isn't water soluble. It can't be taken up by the roots of your plants. It takes a long time to break down, even if you throw them into your compost pile - which is still fine, because they help to aerate the soil.

You can still use them to add calcium to your soil, though! Vinegar breaks down calcium carbonate and turns it into its water soluble form, which plant roots can access. This vinegar/shell fertilizer doesn't raise the pH of your soil, because the chemical reaction neutralizes the acid in the vinegar!

The process goes like this:

- Bake the shells to remove moisture and sterilize them.
- Grind them down finely.
- Add equal amounts shell + vinegar.
- Mix with water.

Voila, a functional calcium fertilizer!

Click here for the recipe in detail.