oh careful now haha i ordered some free stuff probably three years ago..........Discovered now I ordered too many hahahaha, but now I can ship packages out anyway I want. I really like the new padded envelopes. I also miss the old small flat rate boxes that you used to be able to put like a whole potted plant in.
Oh, the humanity!!
Ha, I've ordered free boxes from USPS once before, but not to be used for shipping plants.
Freshman year of college we decided to prank a friend of ours on the second floor of our dorm. So, we went on to USPS.com and ordered 1,500 large flat rate mail boxes (turns out that's the maximum you can order... in case anyone REALLY needs that 1,501st box!)
We built each box and filled this guy's dorm room wall to wall, floor to ceiling with flat rate boxes! The dude opened his door and just saw a wall of USPS boxes... the look on his face was priceless.
Then he chucked all the boxes out into the hallway, and the entire hall of the dorm was knee-deep in boxes. After security showed up, the cleanup job was NOT FUN!
There are a lot of places you can get supplies. USPS is pretty popular but UPS and FedEx have supply shops too. They will have sales on free boxes and other supplies so I stock up there. I also use places like Stamps.com or Brown & Pratt too. But a good place, is Subway. They have good, smaller sized boxes you can have for free if you ask.
Hope those suggestions help.