tend to require more care and attention than most other vegetables.
The potato has specific soil requirements, and thorough insect and
disease control is necessary for potato crops. A good yield is 150
to 175 pounds of usable potatoes from 100 feet of row.
A well drained, fine sandy loam soil, high in organic matter, is
preferred. The use of manure, however, may increase the incidence
of potato scab.
If a cover crop (rye or wheat are excellent choices) was planted
the previous fall, it should be turned under before it exceeds 12
inches in height by tilling 8 to 10 inches deep, depending on the
depth of the topsoil. After tilling, level the surface slightly
so furrows can be made. It is best to wait at least a week after
tilling in the cover crop before planting the seed pieces.
Because scab disease (brown corky tissue on surface of tubers) may
be a problem in alkaline or "sweet" soils, the pH should be 5.0
to 5.5. Liberal amounts of fertilizer are required for large yields
of potatoes. Ideally, the fertilizer should be placed in continuous
bands two to three inches to each side and slightly below the seed
piece. However, many gardeners will broadcast the fertilizer before
tilling or spading. Fertilizer rates should be based on results
of a soil test; a typical rate would be two and a half to three
pounds of 8-16-16, 10-20-20 or equivalent per 100 square feet. When
plants are four to six inches tall, band two to three pounds of
fertilizer per 100 feet of row about 6 to 10 inches from the row,
if growth is not satisfactory and if foliage is yellowish-green.
Use only certified disease-free seed. Such seed is grown under rigid
rules and carefully inspected by state authorities. The potato seed
is not a true seed, but modified stem tissue known as a tuber. The
true seed of the potato occurs in the small, inedible orange fruit
the plant produces during mid-season.
Some feed and garden stores sell B-size seed-small tubers weighing
1-1/2 to 2 ounces. These tubers should not be cut before planting.
If 4 to 6 ounce or larger tubers are used, cut them so that each
piece is block shaped, contains at least one good eye or bud and
weighs about 1-1/2 ounces. Plant immediately after cutting.
Plant the seed in shallow trenches 3-1/2 to 4-1/2 inches deep and
cover with an inch or two of soil. The seed pieces should be spaced
9 to 12 inches apart in rows 28 to 34 inches apart. Nine to 12 pounds
of seed will be needed for each 100 feet of row when 1-1/2 to 2
ounce seed pieces are planted 12 inches apart.
Control weeds by shallow and frequent cultivation. Deep cultivation
may cut potato roots and slow growth. When plants are 6 to 8 inches
tall, begin to mound soil around the bases of the plants to start
forming a ridge or hill. By the time the plants are 15 to 18 inches
tall (at last cultivation), the ridge or hill should be 4 to 5 inches
high. "Hilling up" is necessary to prevent greening of shallow tubers.
beetles, leafhoppers, aphids and Colorado
potato beetles are the major insects affecting leaves and stems.
Early Blight and Late
Blight are the major foliar diseases of potatoes. See GreenShare
factsheets on these pests and diseases for specific control recommendations.
area previously in sod may harbor wireworms, white
grubs and other soil insects, which should be controlled before
highest yields and best storage, potatoes should not be dug until
two weeks after vines have naturally died down. This allows the
skins to set and reduces skin peeling, bruising and rot in storage.
harvesting at temperatures above 80 degrees F, potatoes should be
picked up immediately and put in a dark place. Potatoes exposed
to sun and high temperatures will turn green and may rot. Green
skins on potatoes should be peeled off to reveal white flesh before
homes do not have a suitable place to store potatoes for more than
four to six weeks. To store potatoes for several months, the tubers
should be cured in a dark place at 60 to 65 degrees F and a humidity
of 85 percent or higher for 10 days. After the tubers are cured,
keep them in a cool (40 to 45 degrees F), dark place with high humidity.
Most varieties will not sprout for two to three months under these
E.C. Wittmeyer, Marianne Riofrio and Mark Bennett, Ohio State University