You cannot plant just the eyes of the potatoes as they will not grow properly.
In order for the potatoes to grow from the eyes they really need the energy that is in the potato so you should cut the eyes off the potatoes with part of the potato intact.
Then plant the cut part of the potato with the eye and then water.
Be sure to bury the potato eyes at lest 6 inches deep.
To grow potatoes from the potato eyes dig a trench that is 6-8 inches deep.
Next plant each piece of potato (cut side down, with the eyes pointing up) every 12-15 inches, with the rows spaced 3 feet apart.
If your space is limited or if you would like to grow only baby potatoes, you can decrease the spacing between the potato plants.
You can expect at least five to six new potatoes for each potato you plant.
There's something so magical about pulling up a potato plant and seeing so many new potatoes attached to the small one you planted months ago.
A potato that has grown eyes is still safe to eat so long as it's firm to the touch and its skin isn't shriveled.
Sprouts, however, are not edible and should be removed and tossed.
Small new potatoes can be ready as early as ten weeks.
However, full sized potatoes take about 80-100 days to reach maturity.