Just trying to think of something to freestand or attach to the wall to help with the rose trellis. My first thought was they were along a wooden fence but then you said wall so brick fence or are they along your house wall? No shade there from the afternoon sun?
The two rose climbers are against the back wall. That wall is made of wood with a white wood trellis nailed to it. He put a spacer between the wall and trellis so there would be a little space between the trellis and the wall so plants could send limbs through that space.
The tall brick walls are on the two sides of the garden, not across the back. The back wall and trellis get killer hot in the summer here. I read about that condition and it also happens in Arizona. It says the plants are “scorched” by the sun and they die. I saw pictures of that in Arizona and those scorched plants looked like my dead rose vines.