That may work...I thought once everything grew in, the petrified wood would hardly be able to be seen. I definitely think the large one is distracting for sure, it's just pretty and I dont know what to do with it.
I would have to agree with wrm130 the flat rocks in front need to go, too distracting.
Move the big plant to one of the corners. You could also try laying some of the pointy rocks flat or do a cluster of all of them around a piece of wood. Too many rocks pointing up.
I used to keep an open mind but my brains kept falling out.