Adding egg shells to your garden
Today I wanted to share my thoughts about adding egg shells to your garden. While I understand the thought process behind why folks add their ground up egg shells to the garden, I am going to explain why I believe it is a mistake to add them.
Why are egg shells needed in the garden?
You will see lots of folks recommend adding their egg shells to the garden because they contain some of the calcium that all plants need. Calcium is one of the many nutrient that all plants need. Nutrients is law 5 of the Six Laws of Plant Growth in the Mittleider gardening method. If you want to learn more about plant nutrition then the Grow Food website is a terrific place to get started.
Some plants, like tomatoes, are heavy calcium feeders and will need supplemental calcium. Insufficient levels of calcium manifest in tomatoes as blossom end rot. Have you ever seen blossom end rot on your tomatoes? You likely had a calcium deficiency in your garden.
For areas with 20 plus inches of rainfall, the calcium helps to amend the pH. When the garden soil pH is outside of acceptable levels the plants are unable to use most of all the available nutrients. If your pH is not correct your garden will suffer.
So what is wrong with the egg shells?
Is there something wrong with adding the egg shells to your garden? No. The egg shells are not going to do any harm to your garden. But they are also not going to help your garden when it actually needs calcium.
Plants need their nutrition to be inorganic
Understand the items in the rest of this paragraph can make you a better gardener. Plants need their nutrients in the form of a water soluble, inorganic material. The nutrients and plant does not take from the air are absorbed with water in through the roots.
Egg shells are organic and are not water soluble. Until they are are converted to an inorganic state they simply wont be of any use in your garden.
Can I just wait for the egg shell to be converted to inorganic?
Sure, you can wait. But I do not think you should. First off, there is no real way to determine when the organic egg shells are actually going to be converted to that inorganic state and become water soluble. It could be a year or more until it is available to the plants. When it does finally become available we really do not know how much is available and if it will be enough for the plant.
What can I use to provide calcium to my garden?
To better provide calcium to your garden you can use either gypsum or lime, Typically speaking, areas that receive less than 20 inches of annual rainfall will need gypsum. If you get 20 or more, then you can use lime like we do. It is available at most farm supply and garden stores and is relatively inexpensive. We get ours in 50 pound bags and it typically lasts us several years.
If you would like to experiment a little and try adding calcium to your garden, such as to fight blossom end rot on your tomatoes, you can try something like the Bonide Hydrated lime. If you are in a law annual rain fall area then try gypsum, known as Calcium Sulfate Dihydrate.
Video discussing why I don’t add egg shells
Recently I recorded this video while I was starting seeds and discuss my thoughts on adding egg shells to your garden. It mirrors much of what you read here. You can watch me getting seeds started in a seedling tray as I discuss it.