I've got an October Glory that I just bought and planted a month ago.....it's very young. What are these spots on the leaves? I went back to the nursery and the other October Glory's have the same spots. A worker there told me it's a normal fungus that isn't harmful and will go away.
Based on the fact that the brown spots start from the edge of the leaves I would first suspect that some insect has deposite something there. I wouldn't get to excited about the problem.
What I would do is boost the soil a bit perhaps with an organic fertilizer. This will give the tree a fighting chance against whatever the problem is.
Well, I don't promote particular brands but, liquid fish, liquid seaweed, kelp meal, rock phosphate and so on are great fertilizers. I would actually add a little rock phosphate combined with a few handfulls of kelp meal around the feeders (the soil below the outset of the leaves) of the plant.
Water the plant after adding these slow release fertilizers.