I've been saving decent containers of various kinds for a while. My family calls this stuff Filipino tuperware. I also save many cardboard boxes for planting.
I save containers of all types, glass jars with lids, plastic vitamin bottles, cardboard boxes, plastic pots, glass bottles and jugs, etc., they are part of my preps. My family considers them and all of my other preps junk, but it's my junk in my barn!