Cut them into pieces so that each piece has at least one eye and is roughly at least an ounce.
If you decide to cut your seed potatoes, cut them into pieces so that each piece has at least one eye (though more than one eye per piece is fine too) and is roughly at least an ounce. Then allow the seed potatoes pieces to cure in a cool but humid place for 2-3 days. You can also sprinkle the cut seed potatoes with an anti-fungal powder at this time. After curing, they should be planted as soon as possible. If you are concerned that the weather may get too warm or too cold too fast in your area, you can try chitting your seed potatoes to help get a jump on the season. Plant the seed potatoes about 2-3 inches deep and about 24 inches apart. Seed potatoes can be planted whole, or cut into pieces with at least one eye per piece. Seed potatoes with more eyes will grow to produce a larger quantity of potatoes but the potatoes will generally be smaller. Seed potatoes with fewer eyes will produce fewer potatoes, but those potatoes will tend to be larger. This prevents soil-borne diseases from infecting your potato crop. Plant your whole or cut seed potatoes two to three inches deep in the soil. Rows of potatoes should be about three feet apart and the potatoes within the row should be planted twelve inches apart. You do not need to plant a whole, intact potato. Seed potatoes can be cut into pieces, as long as the pieces have at least 1 eye each. An eye is a bud that grows into a new plant. [See photo.] If you've ever kept your potatoes in the cabinet too long, you've probably seen them sprout. It all depends on what you want. You'll want to plant seed potatoes, either from your crop last year or from a seed source. Not from the grocery store produce department. You could just put each potato in the ground and they would grow, but it isn't very efficient. To get the most out of the potato, we cut it into pieces.  Step 1. Prepare the seed potatoes for planting. Divide the potatoes you must cut and the potatoes that do not need cutting. You must cut any potatoes that are bigger than an egg. Separate potatoes smaller than an egg and place them aside because they do not require cutting.  Potatoes grow from small potato pieces called seed potatoes. A mature potato tuber produces buds, with each bud capable of growing into a new plant. Cutting apart large seed pieces allows you to grow multiple plants from a single seed potato.  Once you have your seed potatoes, you may need to cut them into plantable sections. Any tubers that are about the size of a small egg can be planted whole. Larger seed potatoes should be cut into more plantable pieces. Cut the seed potatoes using a clean, sharp knife so that each piece contains at least two eyes. Pieces should be cut with plenty of flesh around each eye, since the plant will utilize this stored food during the first couple weeks of growth. Cut the seed potatoes into pieces at least a day before planting time. Each piece should be no smaller than two inches square, and each piece must have at least one eye. Lay the cut potatoes out on a tray or on sheets of paper towel to dry overnight. Use the shovel or a large spade to dig a trench in the garden where you plan to plant your potatoes. The trench should be between 3 to 4 inches wide and 6 to 8 inches deep. Place your seed potatoes in the trench, cut side down, eyes facing up, each piece of seed potato between 4 and 15 inches apart. If you choose to cut your seed potatoes into smaller pieces, cut them two days prior to planting. This allows the cuts to callus or heal over slightly. This prevents soil-borne diseases from infecting your potato crop. Plant your whole or cut seed potatoes two to three inches deep in the soil. Rows of potatoes should be about three feet apart and the potatoes within the row should be planted twelve inches apart. If your potato crop suffered from scab disease in the past, move your potatoes to a different section of the garden How to Plant Seed Potatoes. Planting seed potatoes at the right time is important. Seed potatoes growing in soil that is too cold and wet may rot while potatoes that grow in soil that is too warm, may not produce well. If you are concerned that the weather may get too warm or too cold too fast in your area, you can try chitting your seed potatoes to help get a jump on the season. Plant the seed potatoes about 2-3 inches deep and about 24 inches apart.
http://www.gardeningknowhow.com/edible/vegetables/potato/seed-potatoes.htm http://lancaster.unl.edu/hort/articles/2008/plantpotato.shtml http://gardening.about.com/od/vegetable1/ss/What-Are-Seed-Potatoes.htm http://morningjoyfarm.blogspot.com/2012/04/how-to-cut-seed-potatoes.html http://www.gardenguides.com/99606-cut-potatoes-planting.html http://homeguides.sfgate.com/cut-seed-potatoes-40990.html http://www.veggiegardener.com/veggies/potatoes/ http://www.ehow.com/how_5587724_plant-seed-potatoes.html http://lancaster.unl.edu/hort/articles/2008/plantpotato.shtml http://www.gardeningknowhow.com/edible/vegetables/potato/seed-potatoes.htm
how to cut seed potatoes to plant