Last Updated on June 15, 2023 by Grow with Bovees
Is there anything that eggs aren’t good for? Your hair, your skin, your heart, weight loss—the list is seemingly endless!
But wait, can you compost eggshells?
Well, turns out that eggs can be pretty great for your garden, too—provided you compost them right.
Composting eggshells requires a proper process of composting to be followed. This may seem like quite an unnecessary expenditure of labor and effort; however, eggshells provide numerous benefits to your garden, from being a great source of calcium to keeping pesky visitors away, while also being cheap, eco-friendly, and organic, and easily available.
And no one’s really complaining about the eggs Benedict for breakfast, either. While we’re on the subject of breakfast, don’t forget that you can use the remnants from your early morning cup of Joe by adding your coffee grounds and any coffee filters to your compost heap.
Additionally, you’re saving the landfills—an increasingly pressing need—from unnecessary waste; folks in the United States alone send nearly a million pounds of eggshells to their landfills. No, not every year—every day.
Why Eggs Are Healthy for Your Garden, in an Eggshell!
The average eggshell is chock full of nutrients—95% calcium carbonate, 0.3% each of magnesium and phosphorus, and trace amounts of iron, manganese, copper, sodium, potassium, and zinc. Yep, all this goodness is what’s being thrown away at nearly a million pounds a day!
Instead, you could compost eggshells and use them, instead of agricultural lime, to effectively reduce soil acidity. In fact, ground eggshell meal features as an organic fertilizer on many Government-provided gardener handbooks and rule lists.
Also, the calcium from eggshells helps plants in the construction of cell walls, enabling faster growth. In plants that are prone to blossom end rot, such as squash and tomatoes, this calcium can do wonders, you can carry out a soil test to find out the state of your garden soil.
They’re great for your worm bin, in your vermiculture or compost bin, and soil, too, providing the necessary grit for effective digestion when ground up.
How Best to Compost Eggshells In The Garden?
Eggshells, since they’re made of minerals, are not technically organic substances. This means that they cannot be decomposed as easily or as quickly as other food wastes. It can take quite some time—years, even—for the eggshells to get crumbly and no longer noticeable in the soil.
Finely Ground Eggshells Are Best
An effective way to speed up the process of composting is by grinding up eggshells. The smaller the shell particles, the better—studies show that finely-ground eggshells in the garden can add calcium, and be just as effective as pure calcium and better than agricultural lime for adjusting acidic soil.
A coffee grinder is your best friend when you want to powder eggshells; obviously, though, don’t use your fancy Baratza to get the job done—you may want to consider a cheaper grinder exclusively for your composting toolbox, to turn your eggshells into a fine powder.
This ground eggshell can go into your compost bin, or you can spread it around in your garden soil and in the planting holes, especially.
If you don’t have a grinder, you could follow the alternate process of boiling and using the egg water instead. Boil around 10 or 20 eggshells and let this mix sit overnight after you’ve taken it off the stove.
Strain the eggshells out the next morning and lo and behold! You have liquid calcium on your hands. With around 4 mg of calcium from each eggshell in the water, two cups of this per plant are sufficient every couple of weeks.
Of course, you can always go the old-fashioned route and use a rolling pin or your feet to crush them into small pieces (the only time when it’s okay to walk on eggshells!). Dry out the eggshells over several days, till the shells become brittle and dry.
Once they reach that stage, put them in a plastic bag and pound/step on them to get them as fine as possible. Remember to wear shoes if you’re using your feet, though!
You can then add the broken shells to your kitchen compost crock along with any more scraps of food or kitchen waste.
Some folks also directly throw eggshells on to the soil, without drying or grinding. While this is not wrong and will also end up decomposing, it will probably only be helpful in the next season—it needs that much time to decompose sufficiently and turn into calcium.
What About Salmonella in The Compost Pile?
A completely valid question, given that Salmonella is found in every type of poultry egg and unwashed eggshells that are directly thrown into the garden are most susceptible to this living bacteria.
Salmonella thrives in your compost pile from where it makes its way to your plants. This is especially dangerous with fruits and vegetables that you can eat raw, such as strawberries, tomatoes and berries. The worst part? You’ll only find out how dangerous salmonella is after it hits your digestive tract.
This really throws the question of compost hygiene into the light and whether eggshells should really be included in the best compost at this high price. However, when you realize there’s a solution, the price doesn’t seem very high!
One way to combat Salmonella is to bake your eggshells in the oven at 170.6 degrees Fahrenheit for all of a single second in moist heat to dry out the egg’s inner membrane and kill Salmonella traces. This also makes grinding much easier.
If you’re going to throw eggshells directly into your home composting system, bear in mind that the eggshells need more than the 130 degrees Fahrenheit that your system will produce, so you need to bring up the heat!
The mixing rule is quite helpful here—two-thirds of high-carbon materials such as hay, paper, dead leaves, banana peels, and coffee grounds, one-third of nitrogen-rich materials such as grass and food scraps, and an inch of wood chips in the pile for oxygen.
Ensure that you turn and aerate the pile, you can use an auger type compost aerator tool to help with this, at least once a week.
To aid in this endeavor, you can invest in a compost thermometer to keep an eye on the temperatures. Additionally, monitor the moisture content; the pile should only contain 40-55% moisture—moist to the touch but no liquid released when squeezed.
If you have the budget, though (around $200), there’s nothing better than an automatic composter. These generate the high temperatures required to compost dairy, fish, rice, and meat waste, including composting bones, which you can find out about here.
If you’re still going to throw your eggshells out directly, consider washing them first, so that the risk of Salmonella is reduced and so that animals don’t get attracted to the scent and treat it as food.
The Final Word
Composting eggshells is surely a possibility and it’s more than a little beneficial to your garden. Eggshells provide quite a bit of nutritional goodness to your garden and keep away pests and certain plant diseases.
However, remember that a finely ground eggshell is way more effective and quicker than large chunks. It may take a little effort, but the payoff is great!
Thus, while it might not be good to put all your eggs in the same basket, know you know the answer to “can you compost eggshells?”, putting all your egg shells in the same compost bin is not a bad idea at all!