If you’re looking for a simple way to feed your garden, you might be wondering what plants like eggshells. This common kitchen scrap is a fantastic, natural resource for many plants in your yard.
Eggshells are packed with calcium carbonate. This is the same mineral that makes up limestone. When added to soil, it slowly breaks down and provides a vital nutrient: calcium.
Calcium is crucial for strong cell walls in plants. It helps prevent common problems and supports overall plant health. Using eggshells reduces waste and saves you money on fertilizers.
What Plants Like Eggshells
Not every plant has a high demand for extra calcium. But for some, it can make a world of difference. Here are the garden favorites that truly benefit from eggshells.
Tomatoes and Peppers
These popular vegetables are the top candidates. Calcium deficiency in tomatoes and peppers causes blossom end rot. This is a dark, leathery spot on the bottom of the fruit.
While inconsistent watering is often the main culprit, a lack of available calcium in the soil makes it worse. Adding crushed eggshells to the planting hole gives them a steady calcium source as they grow.
Leafy Greens
Plants like spinach, kale, lettuce, and Swiss chard use calcium for those crisp, sturdy leaves. A good supply can help them grow more vigorously and resist pests better. Sprinkle crushed shells around the base of these plants mid-season for a boost.
Fruit Trees and Berry Bushes
Apple trees, peach trees, and brambles like raspberries and blackberries use calcium for strong fruit development. It can improve the shelf life and quality of the fruit. Work eggshell powder into the soil around the drip line of these plants in early spring.
Broccoli, Cauliflower, and Cabbage
All members of the brassica family appreciate the extra calcium. It contributes to the firmness and quality of the heads and florets. It also helps these plants withstand temperature fluctuations a bit better.
Squash, Cucumbers, and Melons
Like tomatoes, these vining plants can sometimes suffer from blossom end rot on their fruits. Ensuring adequate calcium in the soil is a good preventive measure, especially for container-grown varieties.
Lettuces and Other Leafy Greens
We already mentioned them, but it’s worth repeating. For a continuous harvest of tender leaves, calcium is key. It keeps the cell walls strong, resulting in that desirable crunch.
Plants That Dislike Acidic Soil
Eggshells can gently raise soil pH over time, making it less acidic. This is great for plants that prefer neutral to slightly alkaline conditions. Consider it for lilacs, clematis, and many perennial flowers.
What About Houseplants?
Some houseplants can benefit too, particularly if you use very acidic potting mixes or water with soft water. Fiddle leaf figs, spider plants, and African violets may show improved growth with a tiny sprinkle of eggshell powder once or twice a year.
Plants to Avoid Using Eggshells With
Do not add eggshells around plants that thrive in very acidic soil. This includes blueberries, azaleas, rhododendrons, and camellias. The slight pH adjustment could hinder their growth.
How to Prepare Eggshells for the Garden
You can’t just toss whole shells onto your soil and expect results. They break down far to slowly. Proper preparation is the secret to making the calcium available to your plants.
Step 1: Collection and Cleaning
Start saving your shells. Rinse them briefly under warm water to remove most of the egg white. This prevents odor and deters pests. You don’t need to be perfect; a quick rinse is enough.
Step 2: Drying Thoroughly
Let the shells air dry completely on a windowsill or paper towel. For faster drying, you can spread them on a baking sheet and place them in a turned-off oven with just the residual heat. This makes them brittle and easy to crush.
Step 3: Crushing or Grinding
How you break them down depends on thier intended use:
- Coarse Crush: Place dried shells in a zip-top bag and roll with a rolling pin or bottle. Great for adding to planting holes or top-dressing garden beds to deter slugs.
- Fine Powder: Use a coffee grinder, blender, or food processor to pulverize shells into a flour-like powder. This is best for mixing into potting soil or for a fast-acting soil amendment.
Step 4: Storage
Keep your prepared eggshells in a sealed container in a cool, dry place. A mason jar works perfectly. They’ll be ready whenever you need them for gardening tasks.
4 Ways to Use Eggshells in Your Garden
1. Soil Amendment at Planting Time
This is the most effective method. When transplanting seedlings like tomatoes or peppers, add a handful of crushed shells to the bottom of the hole. As the roots grow, they’ll access the slowly released calcium right where they need it.
2. Eggshell Powder for Potting Mix
Mix a tablespoon or two of finely powdered eggshell per gallon of potting mix. This is excellent for starting seeds or repotting container plants that benefit from calcium. It creates a well-balanced, nutrient-rich environment.
3. Side-Dressing During the Growing Season
Lightly scratch a few tablespoons of crushed or powdered shells into the soil surface around the base of established plants. Water it in well. This gives them a mid-season boost, especially for heavy feeders like broccoli or squash.
4. Natural Pest Deterrent
The sharp edges of coarse crushed eggshells can deter soft-bodied pests. Create a barrier around susceptible plants like hostas or lettuce. Slugs and snails dislike crawling over the jagged material. Reapply after heavy rains.
The Science Behind Eggshells as Fertilizer
Understanding how it works helps you use them more effectively. Eggshells are about 94% calcium carbonate. The remaining 6% includes magnesium, potassium, phosphorus, and trace minerals.
Slow Release Nutrition
Unlike liquid fertilizers, eggshells decompose slowly. Microorganisms and soil acids break them down over several months. This provides a long-term, steady supply of calcium without risk of nutrient burn.
pH Modification
Calcium carbonate is a base. As it dissolves in soil, it can gradually neutralize acidity. This is why it’s beneficial for gardens with slightly acidic soil but not for acid-loving plants. It’s a gentle change, not a sudden one.
Improving Soil Structure
In heavy clay soils, the particles can help improve drainage and aeration. In sandy soils, they can add body and help retain moisture and nutrients a bit better. It’s a mild but positive physical amendment.
Making Eggshell Water (Liquid Fertilizer)
For a quicker calcium boost, you can make a simple eggshell tea or water. This is usefull as a supplemental feed during peak growing season.
- Boil 1 gallon of water.
- Add the cleaned shells from about 10-12 eggs to the boiling water.
- Remove from heat, cover, and let steep for 24 hours.
- Strain the shells out, storing the liquid in a jar.
- Use the eggshell water to irrigate your plants once cooled. You can dilute it with an equal part of fresh water if you prefer.
This method extracts some of the calcium more rapidly than waiting for soil breakdown. It’s great for a foliar feed or soil drench for plants showing early signs of deficiency.
Common Mistakes to Avoid
Using Whole or Large Pieces
Big shell pieces take years to decompose. Your plants won’t get the benefits in time. Always crush or grind them for any fertilizer use.
Not Cleaning the Shells
Leftover egg white can attract rodents, raccoons, or cause an unpleasant smell. It can also introduce pathogens. A quick rinse solves this problem easily.
Expecting Immediate Results
Eggshells are a long-term soil builder, not a quick fix. Don’t expect yellowing leaves to turn green overnight. Their value is in prevention and sustained soil health.
Over-applying
More is not better. Excessive calcium can interfere with a plants ability to absorb other nutrients like magnesium and potassium. Stick to the recommended handfuls and tablespoons.
Using with Acid-Loving Plants
As mentioned, avoid using them around blueberries, hydrangeas (if you want blue flowers), and other plants that require acidic soil conditions. It can lock up iron and cause chlorosis.
FAQ: Your Eggshell Gardening Questions Answered
Can I use eggshells for all my plants?
No, it’s best for plants with a higher calcium demand or those that prefer neutral pH. Avoid using them for acid-loving species like blueberries and azaleas.
How often should I add eggshells to my garden?
Once a season is usually sufficient. Add them at planting time in spring, or as a side-dressing mid-summer. For pots, you can mix them into the soil at repotting time.
Do I need to bake the eggshells first?
Baking is not strictly necessary, but it dries them quickly and makes them easier to crush. If you air-dry them thoroughly, that is just as effective.
Can eggshell powder really stop blossom end rot?
It helps prevent it by ensuring calcium is available, but it’s not a cure-all. Consistent watering is the most critical factor in preventing blossom end rot in tomatoes and squash.
Will eggshells hurt my worms in the compost bin?
Finely crushed eggshells are excellent in compost! They add grit that helps worms digest food and provide valuable minerals to the finished compost. They do not harm the worms at all.
How long does it take for eggshells to decompose in soil?
Finely crushed shells can take a few months to a year to fully break down and intergrate into the soil. Larger pieces can take several years.
Beyond the Garden: Other Uses for Eggshells
Your extra prepared eggshells have other handy uses around your home and garden.
- Seed Starters: Half eggshells in a carton make perfect biodegradable pots for starting seeds. Poke a drainage hole, add soil, and plant. Crush the whole thing when transplanting.
- Compost Additive: They are a welcome “brown” material in your compost pile, adding minerals and helping balance pH slightly.
- Bird Food Supplement: Mix clean, crushed eggshells with birdseed. Female birds, especially during nesting season, seek out calcium for strong eggshells of their own.
Using eggshells in the garden is a simple, effective practice that connects your kitchen to your soil. It closes a nutrient loop, reduces waste, and gives your plants a genuine boost. By knowing what plants like eggshells and how to prepare them properly, you can make a real difference in your garden’s health and productivity. Start saving those shells today, and your plants will thank you for seasons to come.