These rose leaves are showing the signs of a highly-contagious disease called Black Spot. This fungus causes leave to yellow and fall off the bush and weakens it. Although it's a horrible thing to find on rose leaves, it makes for beautiful images with the variegated colors and spotting. It was unfortunate to see that Black Spot was running rampant throughout the Harry & David garden and the probably reason many bushes had been removed over the past year.