Potatoesrequire well-drained soil. (They will rot under prolonged cold, wetconditions.) If your soil is poorly drained or a heavy clay, considerusing raised beds. Adding organic matter (compost, cover crops,well-rotted manure or leaves) is a good way to improve soil beforegrowing potatoes. Go easy on organic matter sources high in nitrogen(such as manure) and nitrogen fertilizer as too much nitrogen canencourage lush foliage at the expense of tuber production.
Unlikemost vegetables, potatoes perform best in acid soil with pH 4.8 - 5.5.Use scab-resistant varieties with pH above 6.0. Because most othergarden vegetables perform best at near-neutral pH, it’s usually notfeasible to grow potatoes in their preferred pH range, unless youdedicate one section of your garden to growing just potatoes inrotation with cover crops.
Buy certified disease-free seedpotatoes from garden centers or through online or mail-order catalogsfor best results. If you save your own seed potatoes, discard any thatshow any signs of disease. Avoid planting potatoes from the supermarketbecause they may have been treated with sprout inhibitors. They mayalso be less vigorous and more prone to disease.
Cut seedpotatoes that are larger than a chicken egg into pieces about 1 inchacross or slightly larger. Each piece should have at least one “eye”(the bud where the stem will grow from) -- preferably two eyes.Egg-sized and smaller tubers can be planted whole.
Traditionally,cut seed potato pieces are allowed to cure for a few days to a fewweeks before planting. This is because the cut potatoes need highhumidity, plenty of oxygen and temperatures between 50 F and 65 F toheal quickly. If you have excellent, well-drained soil that meets thoseconditions, you can plant the seed pieces without curing. But ifconditions are not right, the seed potatoes will rot in the ground.
Aless risky practice is to put about 5 pounds of cut potatoes into alarge grocery bag and fold the top closed. Keep the bag at roomtemperature for 2 or 3 days, then shake the bag to unstick pieces thatmay have stuck together. Let sit for another 2 to 3 days and then plant.
Ifyou want fast emergence, keep the bag of cut potatoes at roomtemperature until sprouts appear. Some varieties are slow to breakdormancy and benefit from a 2- to 4-week “pre-warming” before planting.Others sprout in just a few days.
Plant about 2 to 4 weeks beforeyour last frost date. The soil temperature should be at least 40 F. Donot plant where you've grown potatoes, tomatoes, peppers or eggplant inthe past 2 years.
One common way to plant potatoes is to dig ashallow trench about 4 inches deep with a hoe. Place the seed potatopieces with their eyes up (cut sides down) about 8 to 12 inches apartin the trench, and replace soil. Space trenches about 2 to 3 feetapart. Stems and foliage should emerge in about 2 to 4 weeks, dependingon soil temperature.
When the plants are about 6 to 8 inchestall, “hill” the potatoes by hoeing soil loosely around the base of theplants to within about an inch of the lower leaves from both sides ofthe row. Repeat in about 2 to 3 weeks. You may want to make additionalhillings, gradually building a 6- to 8-inch ridge down the row.(Hilling keeps the developing potatoes from being exposed to sun, whichturns them green and bitter. Green potatoes contain a chemical,solanine, which is toxic in large amounts.)
Alternatively,snuggle seed pieces shallowly into the soil and cover with a thicklayer of clean straw or other weed-free mulch. Add more mulch as neededto keep light from reaching potatoes. (A foot or more of mulch may berequired.) Tubers grown this way can be easily harvested by pullingback the mulch after the plants die.
A third method if you haveexcellent potato-growing soil is to plant seed potatoes 7 to 8 inchesdeep and skip hilling or deep mulching. The potatoes are slower toemerge, but this method requires less effort during the growing season.Deep planting is not good in cold, damp soils and it requires more workto dig the potatoes at harvest.
Potatoes need at least 1 inch ofwater per week from either rainfall or deep watering. Mulching helpsretain moisture. Keeping the soil from drying out also helps reducescab.
Use row covers to protect from Colorado potato beetles,leaf hoppers and flea beetles. Crush the yellow eggs of Colorado potatobeetles on the undersides of leaves. Remove adults by hand.
