How and Why I Use Eggshells to Fertilize my Organic Garden

How I use Eggshells to fertilize my Organic Garden.
Over the last year I have been investigating the science behind garden practices methods and products in the Testing Garden Assumptions Series.
As a part of this series I have taken a look at a number of resources often sighted as being able to be used to fertilize your garden. I focused on free and local resources because I wanted to see if I could be a little more sustainable and hopefully fertilize my garden for years to come for free.
In order to analyze the fertilizer potential of a material I look at two main areas. The organic macro nutrients such as Nitrogen Phosphorus and Potassium that are required in higher concentrations and the trace elements or micro nutrients that are equally as important however required in significantly smaller concentrations.
Plants require or gain benefit from 21 elements of these 15 are commonly tested for in our analysis. Of the 6 remaining some are not commonly tested for while others such as Carbon, Oxygen and Hydrogen are gasses that are in consistent concentrations in our atmosphere.
So far free and local resources that have shown fertilizer potential are Coffee Grounds, Tea Leaves, Comfrey, Autumn Leaves, Wood ash or Woodchips and even Human Urine. Today I thought I would take a look at another commonly recommended organic amendment Eggshells.
The main recommendation is that eggshells are made primarily of Calcium Carbonate and calcium is required by many plants and is critical for things such as healthy tomato production helping to avoid things like blossom end rot.
The assumption that eggshells have high concentrations of calcium is quite correct. Researchers in the Netherlands had eggshells from a number of sources analyzed and found that the concentration of calcium in eggshells averaged around 390 mg/g or 39% of the shell.
The calcium in eggshells is not immediately available to plants. It needs to be in its elemental form as appose to the calcium carbonate. Some sources recommend treating eggshells with vinegar or acetic acid to release the calcium. Unfortunately while egg shells will react with vinegar it does not release the elemental calcium it simply binds it and neutralizes the acid.

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References:
Research paper from the Netherlands:
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[trinsit]

OH MY GOD! This is it! Thank you! Finally! Someone who's speaking my language! While you're explaining it and actually digging into the micro verse, now these steps make sense! It feels more like taking care of a mini-ecosystem. 😄

[TheSamba]

Not sure if you check comments on these older videos, but I'd love to see a similar analysis on the byproducts of the brewing industry. Spent grain, trüb, and fermenting vat sediments.

I have been picking up and composting all the spent yeast cake and fermenting sediments from a local brewing and have been curious what I'm actually adding. Based on how it acts and smells, I assume it's heavy in nitrogen, but I'd love to see what else is hanging around in there.

[mommadirt]

Great video and another great local and "free" resource. Mr. Dirt and I grind our egg shells in an old coffee grinder and add the "shell powder" to our worm bins. By turn it into very find particles the worms are able to break it down much faster, and grit is needed by the worms as a digestive aid. If soil is not lacking calcium adding crushed shells to mulch or hot compost as you demonstrated is a great way to go.

[alexbull]

You're solid man! You can see how much research you put in. Great job.

[kimbell]

I am so delighted that you addressed the safety issue re using eggshells in gardens. I don't treat my eggshells and have never had a problem (but wasn't aware of the pathogen danger until about a year ago). I was wondering if the danger of pathogens was more of a myth and/or if they would be a non-issue once introduced into a healthy living soil.

[priayief]

Thanks for another informative video. Several years ago I started adding eggshells to my compost but I noticed they took forever to break down. So now I rinse them under hot water (or in dishwater if its available), leave them out to dry then pulverize them to a powder in a cheap coffee grinder before adding to my compost. I have no idea if they decompose more quickly this way but intuitively it makes sense.

As for hot composting, that's my holy grail! I've been trying to create a hot compost for many years without success - can't seem to get just the right mix of greens, browns, moisture and aeration. Maybe this year.

[themaverickprepper]

One year when I was visiting my brother, he showed me the problem he was having with blossom end rot on his tomatoes. At the time I was taking calcium supplements so took a few and ground them up to a fine powder. I sprinkled it around his tomatoes and watered it in real good. He didn't really see how that would do any good but in a few days the problem was gone.

[asupremum]

I have an old meat grinder on my deck that I use to grind the shells. It does a great job

[fassphoto]

Hi Stephen!
My name is River Costa. Congrats for all those awesome videos. You are very detail oriented and that helps a lot!
I think some how we all have a need for NPK ORGANIC HOME MADE FERTILIZER with that in mind, as you show in this video and some others, some or most of us uses regularly Cofe, Banana and Eggs and with the scraps from these, after being someway composted, it will provides very good ingredients for the best NPK, we just need to know they amounts based on what we are planting.
My self, I am in downtown Miami Florida US. In a apt at the 30. So I only have sun in the small balcony the I need to share with my 2 roommates, some sun on the leaving room at the balcony door, and at my bedroom window. So I am planning to plant tomatoes I know I will need lots of calcium and i don't have much space for composting, so I am planning to do composting using a four 5gl buckets tower method. The tomato trees also will be planted in 5gl buckets. Do you have any idea on how should i feel those buckets for the tomatoes trees besides using composting, should i use perlite, pit moss, or anything else. Any idea would be very helpful and appreciated
Please keep up with this awesome work.
bst regards!

[ferjen]

Great video! My grandma used to leave egg shells to dry and months later use them on her plants, on top of the soil. She said it also helped with keeping snails and slugs away. She had the best garden I've ever seen.
It would be interesting to learn about horsetail tea or shave grass tea benefits in gardening.
Thanks for your videos and keep up the good work!!

[yearvet]

Good info, Stephen. Most of my eggshells go into our compost or heat treated and crushed to powder for my worm bins. I heat treated mostly because they broke into powder more easily. Didn't think about destroying the salmonella. I have the same goal as you do. I have been learning to use what is around me in order not to buy fertilizers. Like you I haven't used store bought fertilizer in 2 years.

[D.A.Hanks]

You would need a TON of eggshells to add to a hot compost pile to be able to mix thoroughly, so unless you are friends with with a short-order restaurant, there is a better way for smaller gardens. I have a blender that is used exclusively for garden minerals: Charcoal, (rinsed) eggshells and old drywall. I powder EVERYTHING for a quick breakdown. I mix this into the soil like any other mineral. For immediate use on tomatoes, the shell sand or gypsum sand will dissolve into the vinegar. After it stops fizzing, put the slurry into the bottom of the hole and add whatever else you want before putting the plants in and filling over the roots. It works great. Since a lot of the other things I use, such as sulphur, are acidic, spreading eggshell or gypsum sand helps balance out the pH.

I'm not trying to be a know-it-all here, but I have been the chief conservation officer for the only eastern redwood forest in America, and the sole wild dawn redwood forest outside China since 1995, and just about everything that I have learned about the forest can be applied to the garden as well.

[dakotabob]

I rinse my eggshells and dry them out thoroughly. I have a dedicated electric coffee grinder that I use to powder the egg shells.

[ytthieme]

great vid, I compost the eggshells in compost.... also used crush eggshells in the garden to sprinkle around to discourage slugs

[EudaemoniusMarkII]

I have been wondering about this for a while. Thanks for the great info!

[easilydistracted]

Another wonderful show, I always look forward to Fridays, ti see what other advice or garden assumptions that you approve or disapprove. Thank you for taking the time to film and post your videos. I have also heard the use of animal blood, such as cows blood, in the compost. Sounds a little gory, but some people swear by it.

[randallmuir]

Sorry I sent my previous comment accidentally before it was completed and proofread. But so far you should have gotten the gist of it. The second part of my message addresses the surface area issue discussed in the video. After my shells are dry and my coffee can is full, I crush them down into the can using the bottom of a heavy pint size beer glass. This gets the pieces smaller than a couple centimeters. When my can is mostly full of crushed eggshells, and they are completely dry, I pour them into my Waring blender. By gradually adding the crushed shells to a blender if you pace it right, it will ultimately turn them quickly into an incredibly fine powder. High speed practically takes them to the consistency of flour! I then sprinkle this into my raised beds and blend it into the soil. I also put a higher concentration blended into the soil directly underneath my tomatoes and pepper plants when they are being transferred into the garden. Hope this helps.

[cqammaz]

I have worm bins that are turning my foodscapes into worm casting. I'm hoping to get enough for my second year gardening. Yes, I spent a lot of money buying all kinds of fertilizer for this year's garden. My soil is clay and I'm working to improve my soil. I even bought sand to mix into the soil fin hope of better drainage. As much as I enjoyed my garden It has cost me a lot of money. I'm rethinking my gardening for next year I'm also hoping to follow your suggestion.

[alanmithel]

Hi Stephen. Please make more great videos about different foods, etc., that will add nutrition to a compost pile.

[AndreaVids]

I'm so glad I've stumbled upon your channel, it's so informative! I'll stay tuned for more diy garden tips!