Eggshells
 

Hello friends.

I was cleaning out my fridge for the first time in a while and I discovered two dozen eggs that had expired in the back of the fridge. In an effort to not be totally wasteful, I broke up and washed all the eggshells as I recently read they can be utilized in my orchid hobby.

I believe I read that growers add eggshells or oyster shells to the pots of some orchids. I believe it was orchids that preferred a higher pH and grew on limestone cliffs in nature (maybe pahps or phrags).

Does anyone here add eggshells to alkaline loving plants media? Any advice?

If anyone knows of a list or can list from memory the orchids that would benefit from a little extra pH/KH I would be very appreciative.

Thanks!

I think mostly Paphs. Some of the European terrestrials (like Ophrys) grow in calcareous soils, I add a bit of crushed limestone to those. Other people, who have low calcium in their water may find it useful as a general supplement, those who have the issue will have to weigh in... my tap water has plenty of calcium so I have never been inclined to supplement tap water (it is on the alkaline side so probably wouldn't do much anyway), I use MSU Cal-Mag where I use RO water

Eggshells don't release calcium at any significant rate. That is why they seem to last forever in pots. There are pieces of Aepyornis shells on the beach at the southern tip of Madagascar even though it's been extinct for centuries.

They contain protein which can be degraded by soil organisms to nitrogen fertilizer, so they can be useful. If you enjoy fungus gnats eggshells are just the thing to provide a population explosion.