How to store a mattress in a storage unit?

Hello Friends,

Should I stand the mattress up against the wall, or just lay it flat on the floor? I am storing the mattress for at least 8 months, and I do not want it to get moldy, sag in the middle or encounter any other problems. What is the best way to store a mattress and protect it? Should I wrap the mattress in something to protect it?

Thanks in advance
Michael Bevan

Simmons Mattress