I don't know, I've been wondering that myself, this is the first year I've tried to grow potatoes. I've had one plant flower, but the rest haven't. Mine are in "pots" (one's an actual pot, the other's a large storage box) so I could just dump them out, but.... I'm thinking that I should wait until the plants start to die? Maybe?

That's what I read. I really need to "dig" into this to understand 'taters better. Apparantly there is something that happens as the plant dies back. One source said to cut the plant back and wait a few days to mimic the plant death....but didn't say why.

While only a few actually flowered, and they look the most weary and even brown, the others aren't far behind.

I'm wishing mine were in an actual pot that I could tip over rather than this raised bed.....grins
c

I dug 1/2 of mine this morning. I added more soil for layers of 'taters. Those on the bottom were fill your palm size. Those just above were fill index finger to thumb size. Those on the top were pea size. They were all red lakoda (sp).

c

I've always dug mine after the tops die off, but if you want smaller potatoes, like to boil whole in beans, etc., you can do a test dig to see if they're about the size you need. Generally, anything planted in Feb-March tends to start dying off about June.

I was always told when the plants start to look limp and falling over that it was time to dig. I dug mine yesterday. All nice sized.