Sun Burn

I have a huge learning curve when it comes to desert gardening. I asked my instructor at my class this evening the etiology of this sad part of an otherwise healthy appearing cactus in our front yard (ie it came with the house). She asked if it had Western Exposure (it does) because this looks like too much sun. So now I will move the tiny cactus behind this one and put a flowery bush in its place that will grow to protect it from the sun. I hope it works!