Thank you. It is in an area fairly close to other hibiscus that are not having such a big problem with yellow leaves.
I think this might have happened last year, too. It is an orangey-red one and has been in for a while. I have a fairly new yellow-flowered one and it is doing great. It even seemed to bounce right through the freeze we had with no damage at all. Made me wonder if some colors are tougher than others.
Or maybe it is like real estate -- location - location - location. It seems like sometimes just a very short distance can make a difference in how a plant does. -- like what shcisamax said about the sides of the driveway.
I think the one at Cane with the yellow leaf problem is the same color flower as the one I have with the problem.
I sure like hibiscus though. So beautiful and not an expensive plant here. And I get to lop 'em in half in the spring.