i know that house destroyed the ones in navarda so thats why there is less rads around and more plant life and rad free water but i dont think they would target a park with a nuke what would be the point so there should be less rads in the park as well and more green stuff ands nothing stops radiation better than canyon wall so there sould be more green stuff there if anywere
That isn't the reason, other areas in Fallout have plenty of vegetation and clean water. I think we can assume that the East was focused on more bomb-wise because of the high population. LA for example was also hit very devastatingly by the bombs because it had a lot of people.
Also, there are trees in the canyon and it looks like appropriate vegetation, radiation is not the single deciding factor on whether stuff will grow.
