changing my plans a little. I was going to use two large 25 gallon pots placed side by side along the glass wall, and then stuffing in other smaller pots around them. One problem with just sticking the pots out there though, is there is no "tray" to put underneath them to catch water running out of the drainage holes in the bottom. I've run into this with the pots I've had out there already - and I hate having dirty water spilling all over the deck. What makes it worse is that I share this balcony with a neighbour, and the last thing I want is for dirty water from my plants to run underneath the partition and onto his portion of the balcony. So, I had been contemplating building a tray myself, large enough to fit under both pots. I figured I could go to the hardware store and pick up a piece of plywood and some 1" strips of lumber to frame a ridge around the edges, then wrap plastic around the strips and screw them in place. I think that should do the trick to contain the water - although, it wastes some floor space putting round pots on a large, rectangular tray. I think this could be overcome by making some shims of the same height, to balance out any smaller pots that would be able to be stuffed around the big pots, but wouldn't fit fully inside (or outside) of the homemade water tray.
Then I started thinking, "Hmmmm, what else could I use to grow in besides these round pots?"
It looks like a trip to Walmart is in order tonight, to go browse the Rubbermaid section.