From a botanical point of view, the peanut (Arachis hypogaea) is actually not a nut at all, but belongs to the papilionaceous plants (Faboideae) and to the family Pulses (Fabaceae). Since their fruits ripen in the earth, unlike those of other papilionaceous plants, do not open but remain closed, the fruits are simply called nuts in common parlance. The English name “peanut”, on the other hand, refers more clearly to the relationship between the peanut and the legume pea.
Originally, the peanut comes from the South American Andean region, where it was already cultivated 2,000 years before Christ. Today it is cultivated on a large scale, especially in Africa and the United States. But you can also cultivate it easily in a pot or in a vegetable patch at home.
Appearance and growth
The peanut is a herbaceous annual plant that grows to a height of between 40 and 80 centimetres and forms a tap root about 50 centimetres long. The leaves are pinnate and consist of four individual leaves. The pinnate leaflets are entire and ovate. From May onwards, the numerous golden yellow, approximately two centimetre long butterfly flowers appear. They stand in the leaf axils and are only open for a few hours. During this time they fertilise themselves and then wilt.
The ovary with the ovules forms a fruit carrier which curves and pushes five centimetres deep into the ground. The fruits develop at the tip of the ovary between July and September. This phenomenon is called “geocarpie” or “earth fruitiness”. The two to five centimetre long fruits of the peanut are elongated and round and have a woody, brittle shell. They usually contain two (rarely only one, but a maximum of four) seeds of about one centimeter in length. They are surrounded by a light red thin shell.
Location and soil
The peanut prefers a sunny, warm location and loose, sandy substrate. It can also be cultivated in pots. In this case, a well-drained mixture of potting soil, sand and clay granules is recommended.
The peanut is propagated by sowing. Although you can sow the seeds directly outdoors from June, it is better to prefer plants indoors in a light and warm place (at a constant 22 to 25 degrees Celsius). Use untreated and unpeeled peanuts. If you let them swell overnight, they will germinate better. Then place the kernels about one centimetre deep into pots filled with growing earth. Under foil their germination capacity increases. Always keep the substrate moist, then they will start germinating after about a week
About five to six weeks after sowing, the young plants are transferred to larger pots. From mid-May onwards, you can then plant the peanut in a full sunny bed with permeable soil at a planting distance of 20 x 20 centimetres. Alternatively, the peanut plants can also be cultivated in a large pot with a diameter of about 20 to 30 centimetres on the warm house wall
Water the peanut regularly, but make sure that the substrate is always slightly dry. Avoid waterlogging. Fertilization is not necessary.
Peanut plants do not require pruning
The peanut usually fertilizes itself, only very rarely does cross-fertilization by insects take place.
About four months after sowing, when the plant is withered and yellow, the fruits can be harvested. To do this, carefully lift the entire plant out of the ground with a digging fork. The peanut fruits hang from the root ball, about 20 to 30 per plant. Now you must let the fruits dry well in an airy and not too warm place for one to two weeks before you break open the fruit shells. Then you can roast the peanuts in the oven or pan and salt them as required – and the popular nibble is ready. Peanuts are also suitable for refining baked goods and confectionery. The seeds are used to extract peanut oil and in the USA they are used to make the popular peanut butter
Peanuts can be propagated generatively by seeding (see seeding).
Diseases and pests
The peanut plant has proven to be very robust against plant diseases and pests. However, it reacts very sensitively to cultivation errors such as an excess of watering water or waterlogging and tends to root rot