Here's my fire escape right after I planted it in late April:
And here it is now that it's June and it's grown in:
In total, I've got two kinds of mint, lavender, sage, rosemary, marjoram, basil, parsley, cilantro, marigolds, petunias, euphorbia, zinnias, nasturtiums, orange cosmos, and wild, spindly purple flower that I bought for looks and forgot the name of.
The empty pots are seeded with lettuce and purslane, and morning glories and bachelor's buttons, just planted last weekend. A squirrel dug up all the zinnias, but all all was not lost because a few survived, a few were replaced, and they're already blooming again. We grow nasturtiums because they're edible and Evan really enjoys them on his salads. Now that the herbs have filled out, I can start thinking about different pestos.
And that is what you can fit on a fire escape. Don't worry, I usually keep an escape path clear, but had to rearrange a bit for photos.