I love finding different ways to help my garden grow, and when it comes to not spending money it’s a win – win! I also keep reminding my boys how important recycling is so bonus teachable moment at home!
Though nitrogen, phosphorus, and potassium are most vital for healthy growth, calcium is also essential for building healthy “bones”—the cell walls of a plant. Composed of calcium carbonate, eggshells are an excellent way to introduce this mineral into the soil. To prep the eggshells, grind with a mixer, grinder, or mortar and pestle and till them into the soil. Because it takes several months for eggshells to break down and be absorbed by a plant’s roots, it is recommended that they be tilled into the soil in fall. More shells can be mixed into your soil in the spring.
By the same token, finely crushed shells mixed with other organic matter at the bottom of a hole will help newly planted plants thrive. (Tomatoes especially love calcium.) For an exciting recycled garden cocktail, try mixing your eggshells with coffee grounds, which are rich in nitrogen.
Finally, eggshells will reduce the acidity of your soil and help to aerate it.
Next, with a nail or awl, make a hole in the bottom for drainage. Add soil and seeds according to the packaging. When sprouts appear, plant them—egg and all—right into the soil. See a complete DIY at 17 Apart.
Apparently you can also use egg’s insides to deter deer. See DIY: Homemade Deer Spray. Be aware, however, that while deer hate the smell of eggs, rodents love it. Therefore, it may not be best to use this deterrent near the house.
Many gardeners also tout the use of crushed eggshells as a snail and slug repellent. But a recent test by All About Slugs in Oregon seems to have dispelled this. If you’ve had any success with eggshells as slug repellent, we’d be curious to know.