Growing and Harvesting Process
Thousands of farmers and their families in 15 states plant, nurture and harvest peanuts every year. Peanuts are grown commercially in 15 states: Georgia, Texas, Alabama, North Carolina, Florida, Virginia, Oklahoma, New Mexico, South Carolina, Louisiana, Arizona, Arkansas, Mississippi, California, and Tennessee. USA peanuts are planted after the last frost in April through May, when soil temperatures reach 65°—70°F. Farmers plant specially grown and treated peanut kernels from the previous year's crop about two inches deep, approximately one to two inches apart in rows. Pre-planting tillage ensures a rich, well-prepared seedbed.

Peanut seedlings crack the soil about 10 days after planting and grow into a green oval-leafed plant about 18 inches tall. Unlike most plants, the peanut plant flowers above the ground, but fruits below ground. Yellow flowers appear about 40 days after planting. Once the flowers pollinate themselves, the petals fall off as the peanut ovary begins to form. This budding ovary, called a "peg," grows away from the plant on a vine and penetrates the soil.

Peanut farmers generally follow a three-year or longer rotation pattern with cotton, corn or grass crops. Peanut plants need 1½ to 2 inches of water per week during kernel development. If rain does not meet those needs, farmers will irrigate the fields. Without adequate rainfall, non-irrigated peanuts begin to show drought stress.

Peanuts are typically harvested 120 to 160 days after planting. The harvesting process occurs in two stages. The first stage, digging, begins when about 70% of the crop has reached maturity. At optimum soil moisture, when the soil is neither too wet nor too dry, a digger-inverter is pulled by tractor through the field. The digger-inverter loosens the plant and severs the taproot with a horizontal blade running about four inches below the soil surface. The digger-shaker lifts the plant from the ground, gently shakes the soil from the peanuts and inverts the plant upside-down in windrows to cure (or dry) in the sun for two or three days.

Combining is the second phase of the harvest. After drying in the field, a combine separates the peanuts from the vines, placing the peanuts into a hopper on the top of the machine and depositing the vines back in the field. Freshly dug peanuts are then placed into peanut wagons for further curing with forced warm air circulating through the wagon. In this final stage, the moisture content is reduced to 10% for storage.

Shelling & Grading
Once peanuts have been harvested and cured, they are called farmer stock peanuts (harvested peanuts that have not been shelled, cleaned or crushed) and are inspected and graded while still in the shell to establish their quality and value. Several samples from each peanut wagon from every farm must be taken and inspected before they can be sold. U.S. peanuts must be certified as safe for consumption. Peanuts certified as wholesome (more than 99% of the U.S. crop last year) are graded by size and type according to industry standards and then sold to product manufacturers.

The inspection and grading of peanuts by the Agricultural Marketing Service of the U.S. Department of Agriculture occurs at buying stations or shelling plants. A random sampler withdraws a representative quantity of peanuts from a wagon, and from this sample the USDA inspector determines the value of the load of peanuts.

Once graded, peanuts move on to the shelling process where they are first cleaned, and stones, soil, bits of vine and other material are removed. The cleaned peanuts then move by conveyor belt to shelling machines in which the shells are removed from the peanut kernels. They then pass through updraft air columns that separate the kernels from the hulls. The kernels then pass over the various screens, where they are sorted by size into market grades.

The edible nuts are individually inspected with electronic eyes and video or laser sorters that eliminate discolored or defective kernels as well as any remaining foreign materials. Once the peanuts have been shelled they are packed into bags, boxes or railcars for delivery to product manufacturers. How would you like to be a USA peanut farmer?

Check out The Peanut Store to order your very own peanut growing kit.