Can't remember who did the beautiful walkway with hypertufa leaves. I do remember that person was in zone 9. I'm wondering if I do this (will do flower/garden border so it won't be walked on) can I leave it out during the winter or will I have to put it in the garden shed?? After doing all that work I will want it to last for at least 5 years. The temps do get down to -30 at times. The mix I use is Quickcrete sand mix and I add a little vermiculite to lighten the weight of the leaves. How would this hold up in snow/ice/cold?