Bismarck.Laurelli said:
»This is my first necro, but it's the best place to ask. I planted potatoes on May 3rd. I wasn't able to get proper seed potatoes because of all the stuff going on right now. So I used sprouted grocery store potatoes.
It's been a pretty cold spring, was about 9-11C until about May 11, and today is the first day over 20C.
I planted them 4 inches deep in a raised bed in soil mixed with compost, but I didn't use any other fertilizer. I topped it all with cedar mulch.
I still don't see anything growing out of the soil yet. Is this normal? Do they need lots of water or should I let the soil get dryer? I'm pretty new at this so any help would be appreciated.
I planted some sprouting store bought russets mid March pretty much the same way you did, about 4" deep in loose soil in a plastic planter box to start them (first time attempting potatoes). I had them popping out of the soil about 3 weeks later, but they were already about 1.5" - 2" before getting them in to the box. From my experience, they take a while to start out but then take off once they establish themselves. They also will need a decent amount of water... pretty thirsty plants. Did you dry the sprouting potatoes out a bit prior to planting them? The potato chunks should have a somewhat rubbery texture. From what I've read, this helps protect the sprouts from disease and help them adapt to new soil.
After the sprouts got an inch or two above the soil, I put them in the ground and then they just exploded. They're pretty hardy plants and should be pretty forgiving. I'd say just wait a little while longer and you should see something. Good luck!
Chanti's advice is spot on, too. Keep mounding dirt up to the leaves to encourage tuber growth. If you see anything that's white on the plant, cover it with dirt or mulch or whatever. Sunlight on the white parts of the plant causes the potatoes to develop a toxin (alkaloid?) and makes the tuber taste bad... also poisonous.