7. As a Draining Layer Use them as a drainage layer for your garden beds (or any other area that needs extra drainage). Just place some eggshells in the bottom of your raised beds before adding soil or compost, then water well after planting or transplanting seeds or plants into their new home! The shells will naturally decompose over time, but they’ll also help keep moisture where it needs to be—which means no more soggy soil underfoot when you’re walking through your garden with bare feet!
8. For Soil Amendment
Adding eggshells to top soil will help improve its structure by adding calcium and other minerals that plants need in order to thrive! Soak some up in a bucket or pail and sprinkle over your beds before tilling them.
9. Pest Control Eggshells can be used as an organic insecticide, especially if you add other ingredients like vinegar or borax. You can also make your own spray by mixing one part of vinegar with two parts water. Spray on plants that have been infested with pests, then leave them on until completely dried out, before removing any dead insects from the leaves or roots.
10. As a Pest Deterrent
Are you tired of washing snails and slugs off of your veggies every time you’re preparing a meal? Your eggshells are the answer to your problems. For this to work perfectly, you will need to crash the eggshells into small pieces (not grinding). The end product should be small pieces with sharp edges, which are the catch for this role. The sharp edges abrade the sensitive feet of the mollusc, therefore, deterring them from accessing your garden. After a while your garden will be free from snails and slugs since they will move elsewhere in search of easily accessible pickings.
11. As a Supplement for Your Birds If you’re a bird farmer then you know how bad it can be to walk into your birds eating their own eggs. Birds normally require calcium before they start laying and after. If they don’t acquire these nutrients from their feeds, then they turn to their eggs to resolve their calcium deficiency problems.
Feeding grounded eggshells to your birds alongside other seeds is the best idea to keep them healthy and to avoid losing the eggs. But before you can feed the mother birds with the shells, ensure that they are sterile by baking them for at least 10 minutes at 120 degrees Celsius.
Ref: https://selfsufficientprojects.com/11-ingenious-uses-for-eggshells-in-your-garden/
