Fun FactsHow The Peanut Plant Grows
The peanut is unusual because it flowers above the ground, but fruits below the ground. Typical misconceptions of how peanuts grow place them on trees (like walnuts or pecans) or growing as a part of a root, like potatoes.
Peanut seeds (kernels) grow into a green oval-leafed plant about 18 inches tall which develop delicate flowers around the lower portion of the plant. The flowers pollinate themselves and then lose their petals as the fertilized ovary begins to enlarge. The budding ovary or "peg" grows down away from the plant, forming a small stem, which extends to the soil. The Peanut embryo is in the tip of the peg, which penetrates the soil. The embryo turns horizontal to the soil surface and begins to mature taking the form of peanut. The plant continues to grow and flower, eventually producing some 40 or more mature pods. From planting to harvesting, the growing cycle takes about four to five months, depending on the type or variety. The peanut is a nitrogen-fixing plant; its roots form modules which absorb nitrogen from the air and provides enrichment and nutrition to the plant and soils.
Photo cred: Texas Peanut Producers.
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Types of Peanuts
Although peanuts come in many varieties, there are four basic market types: Runner, Virginia, Spanish and Valencia. Each of the peanut types is distinctive in size, flavor, and nutritional composition. Within each four basic types of peanuts, there are several "varieties" for seed and production purposes. Each variety contains distinct characteristics which allows a producer to select the peanut that is best suited for its region and market.
- Runner Peanuts
Runners have become the dominant type due to the introduction in the early 1970's of a new runner variety, the Florunner, which was responsible for a spectacular increase in peanut yields. Runners have rapidly gained wide acceptance because of the attractive, uniform kernel size. Fifty-four percent of the runners grown are used for peanut butter. Runners are grown mainly in Georgia, Alabama, Florida, Texas and Oklahoma.
- Virginia Peanuts
Virginias have the largest kernels and account for most of the peanuts roasted and processed in-the-shell. When shelled, the larger kernels are sold as snack peanuts. Virginia Peanuts are grown mainly in southeastern Virginia and northeastern North Carolina.
- Spanish Peanuts
Spanish-type peanuts have smaller kernels covered with a reddish-brown skin. They are used predominantly in peanut candies, with significant quantities used for snack nuts and peanut butter. They have a higher oil content than the other types of peanuts which is advantageous when crushing for oil. They are primarily grown in Oklahoma and Texas.
- Valencia Peanuts
Valencias usually have three or more small kernels to a pod and are covered in a bright-red skin. They are very sweet peanuts and are usually roasted and sold in-the-shell. They are also excellent for fresh use as boiled peanuts. New Mexico is the primary producer of Valencia peanuts.
Photo cred: Texas Peanut Producers.
Return to top Where Peanuts Grow
Peanuts are grown in the warm climates of Asia, Africa, Australia, and North and South America. India and China together account for more than half of the world's production. The United States has about 3% of the world acreage of peanuts, but grows nearly 10% of the world's crop because of higher yields per acre. Other major peanut growing countries include Senegal, Sudan, Brazil, Argentina, South Africa, Malawi, and Nigeria.
Peanuts are grown commercially in 13 states: Alabama, Arkansas, Florida, Georgia, Louisiana, Missouri, Mississippi, North Carolina, New Mexico, Oklahoma, South Carolina, Texas and Virginia.
In the United States, six states grow the majority of the U. S. peanut crop: Georgia (which grows about 42% of all U. S. peanuts), followed by Florida, Alabama, Texas, North Carolina, South Carolina, Mississippi, Virginia, Oklahoma and New Mexico. These states are grouped into three regions. The Georgia-Florida-Alabama-Mississippi region (Southeast) grows mostly the medium-kernel Runner peanuts. The Southwest region (Texas-Oklahoma-New Mexico) grows Spanish, Runner and some Virginia type varieties. The Virginia-Carolinas area grows mostly the large-kernel Virginia type peanut. About 68% of all U. S. peanuts are grown in the Southeast, with the Virginia/Carolina area accounting for 13% and the Southwest, about 18%.
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How Peanuts Are Planted And Harvested
Peanuts are planted and harvested with specialized machinery. Peanut seeds are planted about two inches deep, one every three or four inches, in rows about three feet apart. The seeds do best in sandy soil, especially soil rich in calcium. When the soil temperature is warm (65-70 F.) given enough water the seeds will sprout. In about two weeks, the first "square" of four leaflets will unfold above the peanut field. Thirty to forty days after emergence the plants bloom, "pegs" form and enter the soil. The peanut shells and kernels develop and mature during the next 60 to 70 day period. Depending on the variety, 120 to 160 frost free days are required for a good crop.
When the plant has matured and the raw peanuts are ready to be harvested, the farmer waits until the soil is neither too wet or too dry before digging.
When conditions are right, the farmer drives his digger up and down the green rows of peanuts plants. The digger has long blades that run four to six inches under the ground. It loosens the plant and cuts the tap root. Just behind the blade, a shaker lifts the plant from the soil, gently shakes the dirt from the peanuts, rotates the plant, and lays the plant back down in a "windrow," peanuts up and leaves down. When dug, peanuts contain 25 to 50% moisture, which must be dried to 10% or less for storage. Peanuts are generally left in the windrows to dry for 2 or more days in the field, then threshed or combined.
The farmer drives his combine over the windrows. The combine lifts the plants, separates the peanuts from the vine, blows them into a hopper on the top of the machine, and lays the vine back down in the field. The peanuts are then dumped into wagons and cured to 10% moisture with warm air forced up through the floors of the wagons. The peanuts are then taken to be sold at nearby peanut buying stations.
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Peanut Grading, Shelling and Blanching
At the shelling company buying station, peanuts are sampled and graded by the Federal-State Inspection Service to determine their value. The inspectors establish the meat content, size of pods, kernel size, moisture content, damaged kernels and foreign material. The results of the inspection determine the overall quality and value of each load.
After the peanuts are purchased by the sheller, they are placed in dry storage for eventual sale to processors and manufacturers. At the shelling plant, peanuts are taken from storage and cleaned; dirt, rocks, bits of vines and other debris are removed. If they are to be sold in their shells, the peanuts may also pass through a machine that cuts off any remaining stems on the shells. (About 10% of the peanut crop is sold as in-shell peanuts - usually the Virginia and Valencia types.) To sort for size, the peanuts travel over sizing screens that permit the smaller pods to fall through.
Peanuts to be shelled are placed in slotted drums containing screens of different sizes. Rotating peanuts rub against each other until the shells are opened and the kernels fall out. The kernels are sized on screens that permit the smaller kernels to fall through. The shelled peanuts are cleaned again to remove foreign materials. This is done with density separators, electronic color sorters and by visual inspection to ensure that only the best peanuts reach the market. The peanut kernels are then sized, graded and bagged for market.
From the sheller, peanuts are cleaned again and "blanched" before they are used in most peanut foods. Blanching is simply the removal of the reddish skin covering the kernels. In whole-nut or split-nut dry blanching, the kernels travel through warm air for a period of time to loosen the skins. Then the kernels go through a blanching machine where large rollers rub the surfaces of the kernels until the skins fall off. These kernels are checked with electronic color sorters to ensure that blanching is complete.
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How Peanuts are Marketed
Peanuts are sold in various ways. A peanut broker or a sheller may sell the peanuts to the end user - or, a peanut dealer or commission merchant in a large market may buy the peanuts. Peanuts are usually sold to a manufacturer or "end user," who then converts the peanuts to consumer products and markets the peanuts to the public.
Roughly three-quarters of the peanuts grown in the U. S. are used domestically, predominantly as edible products. About one-forth of all U.S. grown peanuts are exported to other countries. Exported peanuts are usually shipped raw, both shelled and in the shell. The major buyers of U. S. peanuts are found in Western Europe, Canada and Japan.
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Peanut Butter/Peanut Spread
About one-half of all edible peanuts produced in the United States are used to make peanut butter and peanut spreads. By law and industry standard, any product labeled "peanut butter" in the U. S. must be at least 90% peanuts. The remaining 10% may be salt, sweetener and an emulsifier (hardened vegetable oil which prevents the peanut oil from separating and rising to the top).
Other similar products which don't subscribe to the 90%/10% rule are labeled peanut spread. Many are reduced fat products with added vitamins and minerals. These standards are subscribed to by the industry to assure consumers of uniformly nutritious products.
The ancient South American Indians were the first to make and eat peanut butter, and one of the peanut foods invented by Dr. George Washington Carver was similar to peanut butter. Historical reference has it, however, that peanut butter was invented by a physician in St. Louis about 1890 as a health food for the elderly. No one remembers the physician's name, although records show that in 1903 Ambrose W. Straub of St. Louis patented a machine to make peanut butter. Also during that period (1895), Dr. John Harvey Kellogg (of breakfast cereal fame) patented the process of making peanut butter for the patients at his Battle Creek Sanitarium, a health food retreat in Michigan.
Basically, all peanut butter is made by a similar process. First the shelled, raw peanuts are roasted and cooled, then the skins are removed (blanched.) Some manufacturers split the kernels and remove the heart of the peanut as well. The hearts can be saved to make peanut oil and the skins left over from blanching can be sold for animal feed. The blanched peanut kernels are electronically sorted or hand picked one last time to be sure only good, wholesome kernels are used in peanut butter.
The peanuts are ground, usually through two grinding stages, to produce a smooth, even-textured butter. The peanuts are heated during the grinding to about 170 degrees F . Once the emulsifiers are added and mixed, the butter is cooled rapidly to 120 degrees F or below. This crystallizes the emulsifiers, thus trapping the peanut oil that was released by the grinding. To make chunky peanut butter, peanut granules are added to the creamy peanut butter. The peanut butter is then packed into containers for sale at stores.
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Roasted Peanuts/Snack Peanuts
To be roasted in the shell, peanuts are cooked at medium heat for about 15 minutes. They may be plain roasted peanuts or seasoned roasted-in-the-shell. The most popular are salted in-the-shell, however the new flavors - cajun and jalapeno are getting accolades from consumers as well. To season peanuts in the shell - prior to roasting- the peanuts are washed and then the seasonings, which are dissolved in water, are forced through the shells by a pressure process. When dried during roasting, the seasonings remain inside the shells. Most often, snack peanuts are shelled, roasted, blanched and salted, (although Spanish peanuts are usually roasted with their skins on.) Peanuts may be roasted in oil or by a dry-roasting process. Peanuts are oil-roasted in continuous cookers that take a steady stream of peanuts through hot oil for about five minutes. After draining, the kernels are salted evenly. Dry-roasted peanuts are cooked in a large oven by dry, hot forced air after which spicy seasonings are applied. The roasted peanuts are then packed in containers ranging in size from bags holding a handful, to large cans and jars. Frequently, peanuts are mixed with other nuts and dried fruits for "health-food" snacks.
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Peanuts are used in candy-making in a seemingly infinite number of ways. A large variety of candy bars combine peanuts (whole, chopped or as butter) with such treats as chocolate, nougat, marshmallow, caramel, other nuts and dried fruits. Peanut brittle and chocolate-covered peanuts are always popular. The high protein content of peanuts make them ideal for high energy snacks. Six of the top ten candy bars sold in the U.S. contain peanuts and/or peanut butter.
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Oil and Other Peanut Products
Applying pressure to peanuts squeezes out their oil. This oil is excellent for cooking because it is tasteless and can be heated to very high temperatures before it smokes. (450 degrees F, which is hotter than most other cooking oils). With hotter cooking temperatures, food will cook faster and absorb less oil. Peanut oil does not absorb or transfer flavors, so the same oil may be used repeatedly to cook different foods.
Specially processed, defatted peanuts are available as roasted snack peanuts; they may be ground into a flour, which can be used to make such foods as high protein drinks and snacks. Or, the defatted nuts may be granulated and added to breakfast or diet bars to raise their protein level.
Partially defatted peanuts can also be flavored to taste and to look (when chopped) like other nuts, such as pecans, almonds and walnuts for use in cooking.
Peanuts can be made into imitation milk, cheese and ice cream. In fact, "cheese"" made from peanut milk is nutritionally superior to dairy products in everything except calcium.
Peanut meal (made from the by-product of peanuts pressed for oil) is an important high protein animal feed.
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Non-Food Uses for Peanuts
The shells, skins and kernels of peanuts may be used to make a vast variety of non-food products. For example, the shells may be used in wallboard, fireplace logs, fiber roughage for livestock feed and kitty litter; and, the skins may be used for paper making. Peanuts are often used as an ingredient in other products such as detergent, salves, metal polish, bleach, ink, axle grease, shaving cream, face creams, soap, linoleum, rubber, cosmetics, paint, explosives, shampoo, and medicine.
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How You Can Grow A Peanut Plant
- Raw peanuts (may be purchased in the produce section of most grocery stores, at health food stores OR by mail order - see Peanut Marketplace for more information)
- Flower pot or container with drainage hole (6-8 inches in diameter)
- Sandy or sandy loamy soil
- Soak peanuts in water overnight
- Fill pot with soil to one inch below rim
- Plant three peanuts 1 to 1.5 inches deep and cover firmly with soil but do not pack
- Keep soil moist (not wet). Maintain a temperature of 65 degrees F or above (80 degrees F is ideal)
"GROWING PEANUTS IN THE GARDEN"
- Climate for Peanuts
For high yields and superior quality, peanuts require a moderate growing period (110 to 120 days) with a steady, rather high temperature and a moderate, uniformly distributed supply of moisture. The growing season should be long, warm and moist, and the harvest season should be dry.
- Soil for Peanuts
Light colored, well drained, sandy loam soils are ideal for growing peanuts. Since the tap root of the peanut plant frequently penetrates to a depth of 18 inches, it is important that the subsoil be deep and well drained and without tendencies to become excessively dry. Peanuts should not be grown on the same land for successive years (alternate with corn, potatoes, etc.).
Raw peanuts with redskins, intact and unbroken, should be used. Seeds may be left in the outer shell, however, germination will be faster if shelled peanuts are planted. (Raw peanuts may be purchased in produce sections of most grocery stores and from health food stores.) Commercial peanut farmers use seeds treated for disease, but this is not necessary for the home garden.
- Soil Preparation and Fertilization
Soil should be worked until loose and prepared into rows spaced 24 to 36 inches apart. Peanuts respond best to residual fertilization that has been applied to the crop preceding peanuts; however, if the area to be planted has not been fertilized during the prior 12 months, then ahead of planting, apply 10 pounds 0-10-20 fertilizer per 1,000 square feet.
Plant as early as possible in spring after there is no danger of frost. Plant only when the soil is moist and at least 65 E F. at seed depth (2 to 4 inches). Space seeds 4 to 6 inches apart at a depth of about 2 inches. Cover furrow with soil and lightly pack. Plants emerge in 10 to 15 days depending on soil and weather conditions. When plants are about one inch high, thin stand to about 8 inches apart. Control grass and weeds. In cultivating, never throw dirt on the peanut plant.
- Further Fertilization
When blossoms appear on the peanut plants, apply Gypsum [calcium (CaSO4) sulphate] in a 14-inch band over the plants (does not burn) at the rate of 15 lbs. per 1,000 square feet. This is essential to the formation of the peanut kernels.
- Growth and Development
As the peanut plant grows and develops, small yellow blossoms appear (are capable of self-pollination). With maturity, these blooms wilt and a stem or peg forms. Gravity pulls the peg downward into the soil where the peanut pod forms. The outer shell reaches full size well before the individual peanuts mature. Each plant produces between 25 and 50 peanuts. Mature plants may be as large as 36 inches in diameter and about 18 inches tall. The peanut plant has a fruiting period of about two months. All pods do not "set" or ripen evenly. The object is to harvest when the greatest number of pods are matured.
When a peanut is ripe, the veins of the hull are prominent and the inside of the hull has turned dark. If the inside of hull is white, the pod is immature. Pull a plant to examine pods for readiness. Dig when about 2/3's of pods on a plant are mature. If the soil is packed down around the plant, loosen it gently. Shake off as much of the soil as possible (if the earth is damp and sticks to the peanuts, shake again later when it has had time to dry.)
- Drying (or Curing)
Allow plants, with peanuts still attached, to "cure" in full hot sun for 4 to 7 days (may be left, turned peanuts side up on the garden row) or inside a dry, well ventilated area (may be hung or spread in garage basement or storage building). Ventilation is important to the curing process of reducing the initial moisture level of about 50% to a safe storage level of about 10%. Inside curing may take from 2 to 4 weeks. When the curing process is completed, peanuts may be separated from the plant and used or stored.
Peanuts should be stored in a cool, dry place. They keep fresh indefinitely when stored in a tightly closed container in the freezer, ready for use.