On Nov 22, 10:50*am, "Ray" wrote:
We have planted coral bark Japanese maples (sango kaku) for several years,
mostly with good results.

Our present one, which is five years old and about 10 feet high, produced a
surprise this fall: The usual brilliant golden leaves, but also, on the top
branches, beautiful orange-red leaves.

It was as if there were two trees growing from the same trunk.

The yellow leaves have fallen, but the orange-red leaves are still there as
of late November.

Any idea what could cause this?

What a nice colorful surprise. Hope it continues for you to enjoy.
Be sure that there are no sucker branches coming out of the soil or
tree base. If there are, clip them off.
I was told by an arborist that they can take over the tree and change
it completely. I believe this may involve
the treee having been grafted to a different root. This also goes for
the contorted varieties of trees.
Nanzi