I am trying to help my Son and Daughter in Law with Landscaping in El Paso Texas. I am from Michigan so the Climate is quite a difference. We planted some Lillies and some kind of Palm looking plant(I don't remember the name of it) but they are all turning brown. We Built raised Garden Beds against a rock wall with pavers and there is absolutely NO shade. Any plant suggestions other that Cactus? They would like some color and do not have a sprinkler system. Gardens are approx 4x4ft.