Your rooftop garden looks really good after your time spent working it. I am using some very cheap plastic pots. Plan to reuse them as much as possible until I can't use them any more though. We do have a couple of plastic recycle bins we do not use. PLan to fill them up and plant something in those as well.
0.00000000 CASHMAP
Plastic is indeed a lot cheaper. And one doesn't cry for hours when they break, not like the clay ones that are so much more beautiful, but heavy and prone to break and cost dearly :-D