I produced a grid with cowplot:
library(ggplot2) library(cowplot) ggg1 <- ggplot(mtcars, aes(mpg,vs)) + geom_point() + theme(axis.title.x=element_blank
This seems to work...
plot_grid(plot_grid(ggg1, ggg2, labels=c("", ""), ncol = 1), ggg3, labels=c("", ""), ncol =2, scale=0.9) + #perhaps reduce this for a bit more space draw_label("xlab", x=0.5, y= 0, vjust=-0.5, angle= 0) + draw_label("ylab", x= 0, y=0.5, vjust= 1.5, angle=90)