There is nothing wrong with it :-) Japanese maples typically have 3 different foliage colors through the season - the very early spring or new growth, which can be quite intensely colored; midseason or the summer coloring, which can be completely different from spring. And finally fall color, which can sometimes - not always - be very similar to the early color.

Also, happy Japanese maples that receive adequate water will often produce sporadic, exuberant new growth in late summer that resembles its spring coloring. That is what yours is doing....pushing forth a burst of late season new growth. That means it is happy and healthy.

There a variety of reasons why some J, maples do not turn red or lose their red coloring. Not all JM's are red leaved to begin with and some redleaved JM's lose their red color with improper lighting. I'd suspect yours never was a redleaved maple. Do you know the cultivar name? Has it ever been red all season before?

agree

but.. did you shear or prune it into that bun shape??

ken

When I bought the maple tree it was red and beautiful. Now 4 years later it has lost its color. As for the shape it has always been this shape, sometimes it grows out but the landscaper will trim the bottom in the spring.

The Acer palmatum understock/ rootstock (the part the "crimson queen" scion was grafted to) has been allowed to grow and "take over" so to speak. If you look for the graft, you'll see that all the green branches are growing from the under stock below the graft. It's a good bet the graft is failing and your only option is to enjoy the green tree or try again with another red dissectum variety. I suppose you could try pruning off all the green branches after inspecting the graft site for problems and determining the graft is ok (after the leaves fall), but you'd need to pre-mark the branches that should be removed. Tie a string or zip-tie around the branches where they attach to the trunk to avoid confusion. In all honesty, I don't think you'll have much success following that course, but it remains an option if you can't tolerate the green tree.

Al

With all due respect to Al, I am not at all sure that is the case of the rootstock taking over :-) The most common rootstock for any type of Japanese maple is the straight species, Acer palmatum. It's easy to produce and inexpensive - easily grown from seed. But it will rarely ever be anything but a typical upright form with typical palmate leaves. Even the weeping dissectums - like 'Crimson Queen' - are grafted to standard A. palmatum rootstock.

If you look carefully at the photo of the 'reverting' tree, the green branches are not growing upright (or even very horizontally) and the leaves are not palmate. The green branches weep and the leaves are dissected.....that does not sound like a graft failure. I have seen a number of those with weeping laceleafs and the difference in appearance is remarkable! There are very obviously two types of trees growing, with the rootstock growing straight up through and above the weeping portion and with a very different leaf shape. And sometimes color.

But that does not mean I fully discount Al's theory either! There are any number of reasons why red leafed JM's change color but rarely to that degree or so completely from red to green. And the color change is typically seasonal as well so the tree would appear as typical - with red leaves - early in the season. I get the impression that is not case here. So having no other valid reason or even a well-considered opinion as to why the severe and almost complete color change, Al's contention that your red laceleaf was grafted on a green laceleaf rootstock is a reasonable explanation.

A photo of the base of the tree graft location should certainly help to clarify things :-)