I have one Red Maple and 2 October Glory Maples planted in my back yard. All about 6-8 feet tall. They are planted in a row about 40-50 feet apart. Red all the way to the back, October Glory in the middle and in the front. The Red and October Glory on the ends are very green and full, and growing great. The October Glory in the middle is yellower, and about half as full. It didn't appear to seed nearly as much as the others. But it does appear that it's is growing and not dying, but just not as well. All were planted at the same time. I do not recall this problem last year, when all 3 looked full and green. Does anyone know what the problem might be?