R ggrides包装图的中线(未中)

I'd like to draw a line through my rideplots for the mean. The built-in quantile arguments draw a line in the style I want, but at the median. How can I draw one at the mean, preferably without using geom_vline() or pluck at the ggplot build object but staying in the ggridges ecology?

#adding a column for the mean of each Species of the iris dataframe
iris_meaned <- iris %>%
  group_by(Species) %>% 
  mutate(mean_petal_len = mean(Petal.Length)) %>% 
  ungroup()


iris_meaned %>% 
  ggplot() +
  geom_density_ridges(aes(x = Petal.Length, y = Species, fill = Species), 
                    quantile_lines = T, quantiles = 2)  + #adding lines for the median
  geom_text(aes(x = mean_petal_len, y = Species,
                label = round(mean_petal_len, 2)), size = 2, nudge_x = 0.03, nudge_y = 0.35) +
  theme_classic() +
  theme(axis.title = element_blank(), 
        legend.position = "None") 

Example with median lines