Hello.....I want to make use of 2 "tub-like" areas situated on the upper part of a waterfall (by swimming pool) made of boulders. Each is about W 20" x L 24" x Depth 11" ....in full sun, hooked up to the yard watering system. I am in Fountain Hills AZ, Phoenix area.
What could I plant there that is at least 2' tall and does not require more than 10 or 11 inches of soil?
Thank you if you can help.
