What's wrong with my Fatsia Japonica?

[Maryjay]

We have a Fatsia Japonica on the right hand side of a south-eastern facing garden, gets sun in the morning but is shaded in the afternoon, then sun again in the evening.  It was doing great until this year, when it started losing loads of yellow and yellow/black leaves, all sizes.  Very bare at the moment, but no yellow leaves now.  Any idea what might have happened?  We put manure down in spring which hasn't rotted down very well, supposedly horse manure.

[juliely]

Are you watering it? Fatsias do need a lot of water.

[Kos]

My Fatsia goes from strength to strength. Its almost constantly in the shade and I rarely water it, but I do throw lots of vegetable waste aound its base. 

I get the odd yellow and black leaves but always get new growth in its place.

Perhaps they don't like high-nitrogen fertilisers such as horse manure- I know carrots don't