(My tree guide thing ;D)
T = Tree
O = Open/I can't plant here
B = House
X = Cut down
Well.. One thing I've found planting trees, is if I'm planting a whole field of them, the one in the middle always dies.
A bit like this.
T T T T T T T
T O T T O T T
T T T T T T T
Perhaps that's what's going on? (Someone correct me if I'm wrong with this? o-o)
You could test if this is actually happening (if you're okay with this) by first.. saving your game. Chop down the trees around the spot the tree won't grow. And then of course digging up the stumps. So.. basically like this:
X X X
X O X
X X X
Plant the tree in the spot to see if it instantly dies or not. If it still dies... I guess leave your game without saving. Maybe it's a dead spot?
I don't know much about these, or if they even exist, but I've heard that there's a patch where nothing grows. I've never run into these patches before.. so I don't really know.
However.. if it lives. Let the tree grow to full size. Then, replant the trees around it, and maybe that'll do the trick.
I don't think Bunnie's house would be the problem.
A tree needs to be one space away from the tree.. liike a this:
B O T
B O T
B O T
(Haha, it says bot.)
If her house is at least one square away.. It really shouldn't be a problem... And you already have trees by her house, so I don't think it's the problem at all.