If you garden then chances are you have either used eggshells in the garden, been told that you should or know someone that swears by them. So let’s take a look at some of the things that eggshells can do for your garden. We will also take a look at some common misconceptions about eggshells in the garden.
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I should warn you at this point in the post that this one is going to be somewhat different than most other eggshell posts. In truth, the outline for this post started with most of those eggshell myths as headers. I was planning to tell you all about them too! But like all my blog posts, I set an outline and then I go and do my research.
The more research I did, the more I ended up moving the headings I had set in my outline to the section I had for eggshell myths. Funny how that works, but I still hold hard to my scientific roots (from my university days) and I never publish a post without doing my research first! So away we go!
3 Myths about using eggshells in the garden
Myth 1 – They act as a slug repellants
People seem to be under the impression that the slugs won’t want to crawl over the sharp eggshells because of their “soft” bodies. I mean it seems to make sense right? In an experiment conducted over at All about Slugs, they proved that the slugs were actually attracted to the items “protected” by the eggshells! Want to know more? You can check out their post here.
If you are dealing with lots of slugs, the best thing you can do is make your own slug trap (more on that in another post). Trust me, it’s going to be way more effective than using eggshells.
Myth 2 – They can be used in place of diatomaceous earth
Nope, not going to cut it. Yes, you can grind eggshells up into a white powder that may look like diatomaceous earth. But that doesn’t mean that it is going to work the same. Diatomaceous earth is a naturally occuring siliceous sedimentary rock. It is naturally abrasive and it is primarily made up of silica from the fossilized remains of diatoms.
Myth 3 – They can be used to start seedlings
Ok so sure they can be used to start seedlings, but it’s not a great idea. I mean in theory you can use a thimble to start a seedling too, but you wouldn’t right? The problem with starting seedlings in eggshells is that they don’t breakdown quickly and they are relatively small. Also, the shells are going to be too strong for small roots to penetrate. One way that can help the roots escape is to give the eggshells a squeeze before popping them in the ground. If you are looking for some ideas on how to start your plants you should check out my post on 8 ways to start seedlings.
Do you need to prepare eggshells for the garden?
This is a topic that is going to make people pick sides like they picked teams in gym class. Some people will be adamant that there is nothing you need to do other than crush them up and use them in the garden. Others will swear by the fact that you need to go through the whole processing of preparing the eggshells before they can be used in the garden. Given the differing opinions, I jumped into research mode before I make my own determination on the subject.
Risk of salmonella?
Whenever dealing with any aspect of chickens you need to be aware of salmonella. You can get it from handling chickens (yes even from kissing them on their cute little heads), eating the meat that is not properly cooked, or from the eggs. Basically, chickens are salmonella factories so you just need to resign yourself to that fact if you intend to interact with them or consume their meat or eggs.
After some research, I find myself on team clean the eggshells. As I mentioned, chickens and salmonella go hand in hand. As I am using them on vegetables that I plan to feed my family, I just don’t see any point in taking a chance. It’s not a lot of effort, so better safe than sorry. All it takes is a bit of water and some time in the oven, if you want to know more check out How to prepare eggshells for the garden.
So let’s get back on track and take a look at my suggestions for how you can use eggshells in the garden.
1. Use eggshells as fertilizer
In order to have eggshells be a source of calcium for your plants, they need to be prepared properly. They need to be ground up extremely finely. Eggshells are made almost entirely of calcium carbonate (CaCO3) crystals (between 95-97%). For it to become available to plants, it should be finely ground and introduce into the soil at the end of the season.
You can do this after you harvest and clear your beds for the winter months. Eggshells do not decompose quickly. So being in the soil through the winter and early spring will help them to decompose sufficiently. This. makes it available for next year’s plants to utilize it. You can add more to the soil in the spring when you add other soil amendments such as compost.
Just a quick note here. If you are hoping that eggshells are going to solve issues like blossom end rot in your tomatoes think again. Say what? Sorry, I’m not here trying to burst bubbles but it does need to be said. You may have heard that blossom end rot is due to a lack of calcium and calcium is definitely involved. But the issue is more related to how the tomato plant processes calcium rather than a deficiency of it in the soil. But I will go into that in a lot more detail in my post about tomato diseases and issues.
2. Feed them to your chickens
First off, if you have chickens then congratulations and I am super jealous. I honestly can’t wait until the day I can have my own chickens and ducks (maybe a few quail too). My current city by-laws do not allow for me to have any backyard chickens. I would love to try and get a backyard chicken pilot project started up. But to do that effectively I have to get myself organized first. If you are lucky enough to be able to have backyard chicken check out these great breeds.
So anyway, if you have chickens then you can feed them crushed up eggshells. But why??? Well as you are aware eggshells are mostly made of calcium and chickens lay lots of eggs. So feeding chickens crushed eggshells is a great free way to provide your flock with some additional calcium in their diet. This helps to ensure that your chickens produce eggs with strong shells. Another alternative is crushed oyster shells, but you are going to have to buy those. So my vote is for the free source that also makes full use of your eggs.
3. Add to compost
Eggshells are going to be great in compost, but within a specific context and that is vermicomposting. Red wigglers (the worms used in vermicomposting) just love to eat crushed eggshells, just make sure they are ground up incredibly small. The grit the eggshells provide helps the worms to grind up the bits of food they are ingesting from your kitchen scraps. Similar to birds, red wigglers have a crop, so the eggshells help with digestion.
Do you use eggshells in the garden? Do you have different experiences with them?
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