Do they save them up until someone asks for them or will they save them if you ask them to?

They will set them aside if you ask them to do so but otherwise they toss them in the dumpster when the bags are full.

They do not, however, mix trash in these bags and they're for grounds only so just walking in and asking them for whatever they currently had yielded me a 10 lbs bag of the stuff the first time I walked into the store.

I put about two pounds on my compost bin the other day and the other 8 lbs. are still in my garage waiting for me to till and amend my new garden bed starting... now (mwhahahah)

If you ask me I think they should switch memorial day and labor day around in the calendar. I work very hard on memorial day and don't labor a bit on labor day, heh.