How To Use Boiled Egg Water In The Garden

Eggshells can make for great composting material, but the water you boil your eggs in can also be useful in the garden. Eggshell water is a nutrient-rich drink for your plants and an inexpensive fertilizer option. Whether you save the water from hard-boiled eggs or you make "eggshell tea" using empty shells, this is a great way to repurpose and get more out of your eggshells. Here's how to use this gardening trick—and how effective this method actually is.

How Eggshells Benefit the Garden

Eggs contain several nutrients that can enrich the soil. The shells themselves mostly consist of calcium carbonate, the ingredient used in garden lime that raises the soil's pH level to make it more alkaline.

Plants need calcium to build cell walls and grow strong new root tips, shoots, and leaves. Calcium also plays a role in fighting blossom-end rot. There are certain fruit-bearing plants, like tomatoes, that will sometimes develop black spots, known as blossom-end rot, on their fruits when the tissue breaks down, and these black spots are caused by calcium deficiency. This can occur because of inadequate calcium in the soil, but inconsistent watering can also lead to plants not absorbing the calcium they need.

That said, do your research on whether or not your plants prefer acidic or alkaline soil. Plants like tomatoes, hydrangeas, eggplants, roses, cabbage, squash, and peppers will love the added calcium boost. However, you should avoid using eggshell fertilizer on acid-loving plants, like blueberries, azaleas, and geraniums, if you already have soil that is veering towards alkaline. It's a good idea to have your soil tested to see how much calcium is already available.

In addition to calcium, eggshells also contain small amounts of potassium, phosphorus, and magnesium—all nutrients that are used by plants during photosynthesis.

How to Use Boiled Eggshell Water

Whenever you make hard-boiled eggs, an opportunity to make eggshell water presents itself. Instead of pouring the liquid down the drain, use it to water thirsty plants in your garden and fertilize them while you're at it. (Make sure to cool the water to room temperature first.) However, you can also reserve the cracked shells when you make a big breakfast or peel them for your deviled eggs for your eggshell water. The recipe and the list of ingredients to make eggshell water are quite simple:

1. Boil a gallon of water.
2. Add 10–20 rinsed eggshells to the water.
3. Allow the shells to sit in the water, soaking and cooling overnight.
4. Strain the shells out of the water, and then water the garden.

That's all it takes. You can pour the milky-looking water directly onto the plant soil for a nutrient boost. We recommend using about 2 cups of the liquid per plant. Do this once a week for maximum results. Eggshell water can also be stored in a sealed container for later use.

How Effective Is Eggshell Water?

You may be asking just how much calcium carbonate your plants will be able to receive this way. According to Jeff Gillman, author of The Truth About Garden Remedies, they will absorb some. As reported by Garden Myths, Gillman steeped one eggshell in water for 24 hours and then sent the water to a lab for testing. The results showed the eggshell-infused water contained 4 milligrams of calcium and potassium.

However, David Austin, a residential horticulture agent at the University of Florida IFAS, notes that you're not getting a big dose of calcium from this method. An eggshell typically contains 2,200 milligrams of calcium, which is a whole lot more than the 4 milligrams obtained by boiling it in water.

"Eggshells will add some immediate calcium to the soil if ground up to a fine powder," Austin wrote. He suggests crushing your eggshells and adding them to your compost pile, or choosing fertilizers that already have calcium.

So if you want to apply a light dose of calcium while watering your plants, go ahead and use your boiled egg water instead of dumping it out and wasting it. Otherwise, collect your eggshells, clean them, and crush them well—or grind them into a fine powder—before adding them to the soil. That way, you get to give both your breakfast a second life and your plants a booster shot to thrive.