I was reading up a few weeks ago on fertilizing and someone, somewhere said that grinding down egg shells would be a good idea to increase calcium in the soil.
Now this made me save some egg shells and peanut casings. My question is, without grinding them down, would it be a good idea to mix it into the soil when planting plants like peppers for example? Would the same apply for, for example, banana peals?
The reason I ask this is because my brother said he wouldn't do it since potting soil already has an over abundance of nutrients and it would likely damage the plants.