Pest
Flea beetleTiny round holes in leaves

Tiny shiny beetles that pepper leaves with small round holes, mostly in warm, dry weather.
When it shows up: Spring and summer, in warm, dry weather
What to do
Cover new sowings with fine mesh.
Keep the soil damp: they hate it.
Older plants grow through it, and the leaves are still fine to eat.
Helps prevent it
Not quite it?
These look similar. Compare the photos.

