"Bhí sé ag cur prátaí."

[pinkfreud]

"It was raining potatoes".

[scilling]

Luckily British Pathé filmed it for posterity.

[Prony-dH-Bray]

Bhí sé ag cur cabáiste...

http://pin.it/wSSo2xg

[Sean_Roy]

To say, "He was planting the potatoes," would it be, "Bhí sé ag cur na bprátaí"?

[SatharnPHL]

Yes, it would.

https://www.duchas.ie/en/cbes/4922325/4870335

[AnSeabhac]

Unacceptable: "he was laying potatoes"?

[Demanbm]

Are there any other phrases with 'ag cur x'?

[SatharnPHL]

ag cur is used in lots of phrases - ag cur allais - "sweating", ag cur fola - "bleeding", ag cur isteach ar/ag cur as do/ag cur ar - "annoying/bothering", ag cur imní ar - "worrying", ag cur brú ar - "pressuring/pressing", ag cur i gcéill - "bluff/pretend/have someone on"

It's also used in the fairly literal sense of "putting":
dá mbeinn ag cur airgid air - "if I was putting money on it"
tá an imní ag cur blianta air - "the worry is putting years on him"

[galaxyrocker]

In the standard both ag cur báistí and ag cur sneachta exist ('raining' and 'snowing'). you could also use it for planting anything

[Olivia741767]

What an Irish sentence

[KittDunne]

So, in context, he might be sweating potatoes. Like sweating bullets.