Nathan asks
"Any suggestions for plants that can tolerate being urinated on often?"
My first idea was a compost bin instead of plants, since urine is a
compost activator. But maybe you can start by mulching with wood
chips before planting (you can get them free from tree trimmers in
most places).
Any weedy plants that like lots of water (so that you can wash them
down each morning if the concentration or odor gets excessive) would
work. A good thick layer of mulch will help absorb the odors and, as
a bonus, create rich soil. Mint is a good choice. If there are any
community gardens in your area, go there and ask the gardeners what's
invasive. Around here, lemon balm, mullein, rhubarb, and artichokes
practically grow on their own (with some added water). Perennials
take time to get large, though. If it's a sunny area, you can plant
some annuals such as tomato plants (some varieties get huge fast) or
squash and think of them as foliage plants. The vegetative growth
will thrive on the extra nitrogen and water; tomatoes will not fruit
a lot with all the extra fertilizer.