I can't see the rest of the bushes but connected trees count too so you mightve exceeded that limitation
Even including the trees there are only 9. I should mention that it refused to grow even before I planted the one to its right. Also there is no connection behind to the bushes behind the trees. It just doesn't make much sense to me.
This is what the rest of it looks like btw.
![KbTAcdZ.png](https://i.imgur.com/KbTAcdZ.png)