Early potatoes can be planted through April 10 as long as the soil temperature is above 45 degrees before planting. Choose a site in full sun and with loose soil. Do not plant in areas sodded last summer because it will increase the chance of certain insects attacking the tubers, especially wireworm.
To prepare the soil for planting, make a furrow three to five inches deep. Add a fourth of a pound of 10-20-10 fertilizer per 75 feet of row and incorporate it into the soil. Later in the season, a sidedressing of seven pounds ammonium nitrate per 10 feet of row should be done at tuber formation (when the potato is blooming) and about six weeks after planting.
To cut down on disease and increase your yield, use clean and certified seed potatoes. Do not use potatoes from the grocery store because they may have been sprayed to inhibit their eyes from sprouting. A couple of days before planting in the field, cut the potatoes into one to two inch pieces — these are your seeds. Each piece should contain two to three eyes or buds. Place these pieces in a bright and well-ventilated spot to cure them.
Plant the potato pieces or seeds in the furrow one to two inches deep and 10-12 inches apart. Each row should be three feet apart. Pull a ridge of soil over each row.
Potatoes can also be grown in mounds. To do so, loosen soil in a three- to four-foot diameter circle. Place six to eight seed potato pieces inside this circle and cover with one to two inches of soil. Regardless of planting method, continue to cover the tubers with soil as they grow. Once the tops of the plants have top growth, throw soil over the potato plant to help prevent exposure to the sun.
Make sure your potato crop receives plenty of water while growing. The most critical time for watering is when the potato is flowering and immediately after bloom. You do not have to worry about irrigating once the foliage turns yellow and dies back. This will allow the tubers time to mature in the ground for a week or two.
For new potatoes, loosen the soil around the plant and harvest at flowering. For mature potatoes, harvest them when the foliage turns yellow and begins to die back. Make sure and dig them prior to frost. Potatoes are best stored at 40 degrees, in the dark.