Peanut seeds come in their shells and can be planted hulled or unhulled. If you do shell them, don’t remove the thin, pinkish brown seed coverings, or the seed won’t germinate.
Related: Start Seeds On Your Kitchen Table
Northern growers should start plants indoors in large peat pots a month before the last frost. Sow seeds one inch deep, place in the sunniest spot possible, and water weekly. Transplant seedlings to the garden when the soil warms to between 60 and 70 degrees. Space transplants 10 inches apart, being careful not to damage or bury the crown.
In the South, plant outdoors around the date of the last expected frost. Space seeds two inches deep and five inches apart in rows 2 - 3 feet apart. Firm the soil and water well. Thin plants to 10 inches apart.
When the plants are about a foot tall, hill the earth around the base of each plant. Long, pointed pegs (also called peduncles) grow from faded flowers and then push 1 - 3 inches down into the soil beside the plant. A peanut will form on the end of each peg. Lay down a light mulch, such as straw or grass clippings, to prevent the soil surface from crusting so that the pegs will have no difficulty penetrating the soil.
One inch of water a week is plenty for peanuts. Being legumes, peanuts supply their own nitrogen, so avoid nitrogen-rich fertilizers, which encourage foliage rather than fruits. Well-prepared soil will provide all the nutrients the plants need.
Related: Feeding Healthy Soil
Peanuts are usually problem free.
The crop is ready to harvest when leaves turn yellow and the peanuts’ inner shells have gold-marked veins, which you can check periodically by pulling out a few nuts from the soil and shelling them. If you wait too long, the pegs will become brittle, and the pods will break off in the ground, making harvesting more difficult. Pull or dig the plants and roots when the soil is moist. Shake off the excess soil, and let plants dry in an airy place until the leaves become crumbly; then remove the pods. Unshelled peanuts, stored in airtight containers, can keep for up to a year.