Plants like tomatoes, peppers and eggplants in particular will benefit from shell fertilizer, Savio said. The extra calcium will help prevent blossom-end rot. Broccoli, cauliflower, Swiss chard, spinach and amaranth are also calcium-packed and could use extra from eggshells.
Don't add eggshell fertilizer to plants that prefer acidic soil, like blueberries. Ericaceous plants such as mountain laurel, pieris and azaleas also fall into that category.
While eggshells are compostable and can be added to your kitchen countertop bin or backyard compost pile, using eggshells for plants is also beneficial. They provide important minerals—namely calcium carbonate, potassium, and phosphorus—that can be absorbed by your plant's roots after breaking down.
Add the ground eggshells to your compost bin to make mulch or pour them directly into your planting holes. Many master gardeners add coffee grounds, which are rich in nitrogen and potassium, to eggshell fertilizer for even more of a nutrient boost.
Egg shells are an organic material and full of calcium which helps plants thrive, so once you're ready to bring them outside, you can put the entire shell into the ground where it will nourish both the soil and your plants.
Just like in the garden, finely crushed eggshells provide an organic source of nutrition for houseplants, patio pots and hanging planters. Sprinkle the pulverized shells on the soil surface and they will break down over time whether you are using eggshells for houseplants or outdoor containers.
Don't throw out those eggshells. Wash and add to your worm composter or use them with your houseplants or in the garden as a fertilizer supplement. Egg shells will add small amounts of calcium, potassium, a bit of sodium, but not enough to harm the plants, phosphorous and magnesium.
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.
Clean Eggshells are Safe Eggshells
Eggs are known carriers of salmonella, which should not be present on uncracked eggs that have been well washed, but you never know. Unless the only place the eggshells are going is into the compost bucket, I rinse them well and let them dry in a sunny windowsill.
Boost potted plants
When potting plants, place a few used tea bags on top of the drainage layer at the bottom of the planter before adding soil. The tea bags will help to retain water and will also leach some nutrients into the potting medium.
Also, on average, the plants with 1 gram and 5 grams grew taller than those without eggshell. However, the results also show that too much eggshell (10 and 15 grams) does not make the plant grow faster. Overall, I learned that a small amount of eggshell enhances plant growth.
Banana peels contain: calcium, which promotes root growth helps add oxygen to your soil. magnesium, which assists with photosynthesis. sulphur, which helps plants develop strong roots and repel pests.
Egg shells are alkaline, which works to neutralize any acid, including those in coffee beans. Using egg shells while brewing your coffee will also reduce any bitter taste that it has as a result of the brewing method you choose or the roast of the beans.
Eggshells are packed with generous amounts of calcium and potassium, which orchids need in order to thrive. This trick is super easy. Simply save eggshells and crush them using a blender or a mortar and pestle.
Eggshells take a lot longer to break down compared to many other compostable goods, and too many of them can increase the acidity of your compost. This shouldn't be a problem, unless you plan on using it to grow plants that prefer low soil pH.
Eggshells ground to a fine powder yield the quickest results, while large chunks of eggshells will take at least a year to break down making their stored calcium plant available perhaps the next growing season.
Eggshell Benefits
As it happens, eggshells can provide all the calcium carbonate the soil needs, which helps to lower the soil's pH level and make it more alkaline as opposed to acidic. This is incredibly beneficial for plant growth because many plants prefer to grow in soil that has low acidity.
Organic gardeners love using eggshells as fertilizer because they are high in calcium, which is great for tomatoes and other calcium-loving plants. Eggshells also help to deter slugs and snails. The main downside of using eggshells as fertilizer is that they take a long time to break down.
Eggshells contain very few nutrients – mostly calcium. Most soil in North America has plenty of calcium. Unless your soil has a calcium deficiency adding more will not help grow plants. They also have a fair amount of sodium which is toxic to plants at even low levels.
Banana peel is the main component in produced organic fertilizer and as a waste product that release carbon source and contains nitrogen, phosphorus and amino acid while egg shell rich of phosphate and calcium that very effective for plant growth. The level of nitrogen and phosphorus will affect the pH value of soil.
In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.
Primarily a rich source of calcium, eggshells help roses by strengthening the walls of the plant's cell tissue. When rose plant parts are at their sturdiest, they are better able to fight off disease and pests.
Enter coffee grounds and eggshells. While we may consider them to be trash, they provide a healthy snack for plants offering a one-two punch of nitrogen and calcium. "The nutrients they add to support healthy plant growth are needed in almost any soil bed," according to Los Angeles-based collective LA Compost.