Tree Square, Redux

If you remember, I planted the little dirt space around the tree out front with various flowers.  They looked really great, and even made the old ladies up the street smile at me when they walked by.
Unfortunately, after a brutally hot July, a day or two of missed watering, and a few dogs who thought it a choice toilet, the flowers bit the dust.
I stopped by Sprout Home, a local garden store, to get some expert advice as to what plants would work well in such a place.  They needed to be hardy in hot weather, dog resistant-ish, preferably perennial, and hopefully green year-round.
They suggested an ivy plant in each corner that would spread over a few years time.  It'll stay green throughout the year and dig deep for water.  Well why not just fill the square with the ivy, I asked, thinking about how that would be an easy solution.  The answer - because it'll eventually choke out the tree, or at least take away too much of it's resources.  Huh.  Almost obvious, once I thought about it.
So, I ended up with some ivies, and a few other flowery plants and desert greenery that, while they won't last through the winter, will be ok with the heat and dryness.
Here's how it's looking:

It's not as pretty and colorful, but hopefully it'll last.
Now, if only I could find something to plant that would stop people from throwing their cigarette butts here...