Causing item to place a block on top of clicked block instead of replacing it

I'm trying to cause my item to place down my bush block on top of the block being clicked. Right now, it replaces the block being clicked with the bush, but I need it to place the block on top. How may I do this? My current code:

@Override
public EnumActionResult onItemUse(ItemStack stack, EntityPlayer player, World worldIn, BlockPos pos, EnumHand hand, EnumFacing facing, float hitX, float hitY, float hitZ){

	worldIn.setBlockState(pos, BerryBushRed.instance.getDefaultState(), 3);

	return EnumActionResult.SUCCESS;
}