Any Tips for Burying Gold and Silver?

Hi There!

The safest place for me to stash my stash is in my backyard, underground a few feet. I am not much concerned with confiscation or metal detectors.... at this point.

While some may disagree with the outdoor, underground decision ( I wouldn't mind discussing that either), my main objective here is to find out a good method for actually burying the metals without doing them any damage.

I've read that PVC in any form is very bad for storing metals, which kind of blows the idea of a PVC pipe capped and glued at both ends; but if the PMs were wrapped in something first, and then put in the PVC pipe... would that be ok? Should each coin be wrapped separately before being stored? In what??? Humidity has to be taken into consideration as well. Metal will rust. Glass?

If anyone can shed some light and/or experience onto this endeavor ( I EXK!!!!!!), I would greatly appreciate your input.

Thank you in advance.