Answer: This is a bit mystifying. The most common reason for lack of fall coloring is that the plant is growing in too much shade, but these are in full sun. There can be some genetic variation between plants that would account for the difference if they were seedling grown. The difference is size is most likely due to how well the plants have managed to establish their roots. The small one most likely is not rooting as well as the other two. Again, however, there can also be some genetic variation in growth rates. I'm sorry I can't give you a more specific answer.
Q&A Library Searching Tips