I am building a directed graph using tidygraph and ggraph.
The issue is that arrow tips extend inside rectangular node labels created with geom_node_label(), making arrow direction difficult to see.

I tried:

• Increasing figure size with ggsave()

• Changing arrow length

• Using end_cap = circle()

But circle() applies a fixed radius and does not respect the rectangular geometry of geom_node_label().

Is there a way to automatically clip arrows to the border of rectangular node labels?

Here is a minimal reproducible example:

library(tidygraph)
library(ggraph)
library(ggplot2)
library(grid)

nodes <- data.frame(
  name = c(
    "Sun exposure",
    "Deadwood volume",
    "Altitude",
    "Wood-inhabiting fungi\nComposition",
    "VOC\nComposition",
    "Arriving beetles\nα-diversity"
  )
)

edges <- data.frame(
  from = c(
    "Sun exposure",
    "Deadwood volume",
    "Altitude",
    "Wood-inhabiting fungi\nComposition",
    "VOC\nComposition"
  ),
  to = rep("Arriving beetles\nα-diversity", 5)
)

graph <- tbl_graph(nodes = nodes, edges = edges, directed = TRUE)

ggraph(graph, layout = "sugiyama") +
  geom_edge_link(
    arrow = arrow(length = unit(4, "mm"), type = "closed"),
    end_cap = circle(6, "mm"),
    lineend = "round"
  ) +
  geom_node_label(
    aes(label = name),
    size = 5,
    label.padding = unit(0.4, "lines")
  ) +
  theme_void()

In this example, the arrow tips overlap the rectangular labels.

How can I make arrow tips stop exactly at the label border (respecting the rectangular dimensions)?