July end of the month view - can you help my tree?

I actually didn't forget the end of month view that I've been joining in with Helen from The Patient Gardener, but just couldn't take pictures of this area in the state is was in.  It needed some serious cleanup and I finally had a chance to do some today.  The Japanese Maple 'Orido Nishiki' in this bed isn't looking so great right now and I'm hoping someone may have some advice on what I can do about it.  Everything else in this area looks great and is blooming on time.

I had to cut many flowers from the lower parts of the Hydrangeas.  They were laying completely on the ground.  Because this bed faces northwest it gets very little to no sunlight from the tree back towards the house.  The soil never really dries out especially after the very wet spring and early summer we had and having a gutter downspout draining into this bed I think that could be contributing to the trees problems.

Aside from the tree looking like the middle of September everything else is very happy here.

Fuchsia 'Queen Esther' just started to bloom and the Spiderwort (Tradescantia) is beginning to bloom again.  I probably cut off 20 Hydrangea blooms and it still is full of flowers.

The Hosta behind the little girl has been doing well.  Most of my Hostas are full of holes from the slugs that still are wreaking havoc in the garden.

If you look at the base of the tree you can see it's black in the back.  I remember noticing it in the same place last year, but never thought about it.  Hydrangea flowers were laying right over that place and when I pulled back the flowers to cut them, I found ants and aphids in the black area.

Up close you can see the black looks like oil.  It feels "wet" to touch.

Normally the leaves would still be mostly green and white (it's a variegated variety), but they are turning reddish and then falling off as they do every fall.

So, other than my tree not looking as good as it should I'm still happy with this area.  I think I need to work on drainage in this bed.  My husband suggested we divert the downspout completely out of the bed and then I think I may need to remove some of the heavy clay soil and try and amend with more compost.  The tree has been here for about 6 years and replaced a Vine Maple that literally tipped over one day.  Now that I look back I have a feeling it was because of the poor drainage in this soil that caused it's death.  If anyone has any ideas on what the problem could be I'd love to hear.  The large Japanese Maple on the other side of the house is losing a few leaves, but otherwise looks good.