Mine took about 2 weeks for the first ones to sprout and I am still waiting for some though.
I would say at least half came up in two weeks and the other half is on its 3rd week but I have noticed a real surge in the potato growth since we started this rain a few days ago.
Its a bummer for alot of things but its been great for the garden.
I saw my first potato plants today I am syched! I planted 10 sprouts between my 2 wire bins. I saw leaves on 1 plant in one bin and leaves on 2 plants in the other bin. WEEEEE!
I put mine in the ground Apr 21 and I have been seeing them pop up the last two days, the all blues and cranberry reds, the yukons have yet to poke their little noses up :tools