When you place a bush with Ivern, the fog of war don't work properly, it don't makes you invisible but it's permanant spaces of invisible bush graphic effects like the translucence of invisibility and holes in the fog of war.
You can still see them in the dark, but its realy disturbing and lead to less info, for example when doing the baron where Ivern players put bushes in front of it, it's like you have no idea of where you can see...
And for the plants, I have problems with vision plants and now explosives, where their models stays where they were, even tho they aren't there. And it stacks up, I once had 2 vision plants on the blueside Redbuff and 1 real plant.
Thanks, sorry if i'm too vague.