Add a position offset to x axes titles in R's ggplot

Question

In R. I currently have this ggplot:

And I am looking to get the titles right in the center of the square, like this:

I took a look at ?element_text but there is no position/offset setting. How can I move offset x-axes in a ggplot?

Answer 1

Maybe try with the theme() I have added:

library(ggplot2)
#Code
ggplot(iris,aes(x=Species,y=Sepal.Length))+
  geom_boxplot(aes(fill=Species))+
  theme(axis.text.x = element_text(angle = 90,vjust = 0.5))

Output: