Are Eggshells Good For Plants? Gardening Myths & Truths Explored.

The eggshell is an item of much debate in the world of gardening. People claim that they will do everything from deterring pests to delivering nutrients to your plants, but is it true?

The truth is, while eggshells won’t harm your plants, they won’t do a lot on their own to benefit them. That’s because it takes a really long time for them to break down, but there IS a way to utilize eggshells. Here’s how.

How To Extract Calcium From Eggshells

The easiest way is to crush the eggshells as fine as possible and toss it into your compost or worm bin. Nature will work its magic and break down the calcium into the soil for you to use.

The second way is to create a water soluable calcium spray. Crush the shells, put them on to a baking tray and bake them for 45 minutes at 350 to sterilize them. Then, add the shells to a jar with 10 parts brown rice vinegar to 1 parts eggshells.

Let the mixture sit for 7-10 days and allow the calcium to leech out into the vinegar. Then mix the jar 1 part to 1,000 parts water and use it as a calcium spray for your plants. With this method, calcium is bio-available much quicker.

Do I think this is a good use of your time? Not really. It’s honestly a lot of work for not a lot of benefit, and there are far better ways to make use of your shells in my opinion.

Best Uses For Eggshells

While eggshells don’t do much on their own for your plants, they are very useful to birds. If you’ve got a backyard flock of chickens, crushing up and returning the shells to them in their feed is a good way to keep calcium from depleting in their bodies. Laying eggs takes a lot of out you, after all!

If you don’t have chickens, you can offer the same service to wild birds. Crush the egg shells as fine as you can and mix it into your bird feeders to give them a calcium boost and help them with their egg laying.

Or, if you have no bird friends to feed, starting a compost pile in your yard, or a kitchen compost bin if you live in an apartment is a good way to reduce your waste and create rich soil for your indoor plants or balcony garden.

What About Pest Control?

There’s also a prevalent rumor that crushed egg shells will deter and even kill slugs by slicing them. However, this one also seems to not be true, though it does borrow some truth. Diatomaceous earth is commonly used as a natural pest control for certain insects, as it cuts up their exoskeleton and causes them to lose moisture. This dries them out and they will eventually die from it.

However, there’s no strong evidence that this works on slugs. They are an entirely different animal, and if you’re looking to keep them out of your garden, then investing some time in companion planting is likely a better choice for you, or attracting local predators that feast on them like toads, hedgehogs, and opossums.