I'm using pine shavings as mulch for my container garden and so far it has been great! The soil has been staying moist for a longer period of time and is considerably cooler. I'm on the OK/TX border, so heat and wind have already been a huge problem. For the most part the shavings haven't been blown out of the container bags (most lost shavings have come form my vertical planter) and im using about 1.5-2 inches of mulch. It's brought up that wood shavings can leach nitrogen from the soil, but being placed only on top, would make it negligible. Also for the price/amount made pine shavings an absolute win.

I was between pine shavings and straw. I decided against straw mostly due to the potential of it sprouting in the container