Peanuts are a fascinating crop because unlike most other plants we eat, their fruits develop underground. Known scientifically as Arachis hypogaea, the peanut is not actually a nut at all but a legume, related to beans and peas. This unique plant has a long history of cultivation in warm regions across the globe, and many people are surprised to learn that it is possible to grow peanuts from seed in the UK with the right approach. Planting peanuts can be a rewarding experiment for gardeners who enjoy trying unusual crops, though it requires understanding the specific needs of the plant and its unusual growing process.
What makes peanuts different from other crops
Unlike tree nuts such as almonds or walnuts, peanuts grow as small pods beneath the soil surface. After flowering above ground, the plant produces pegs that bend down and push into the soil, where the pods then form and mature. This unusual method of reproduction sets peanuts apart from most other legumes. Knowing how the plant develops helps gardeners understand why soil quality, depth and warmth are so crucial for success.
Choosing seeds for planting
The first step in planting peanuts is selecting the right seeds. Raw, unsalted peanuts in their shells can sometimes be used, but they must not be roasted, as heat treatment kills the embryo. Special seed peanuts are available from suppliers and are usually more reliable, as they are free from mould and prepared for planting. In the UK, using high quality seed peanuts improves the chances of germination and healthy plant development. Peanuts are best planted in spring, once the risk of frost has passed and soil has warmed to at least 18 degrees Celsius.
Preparing the soil
Peanuts prefer light, sandy soils with good drainage. Heavy clay soils can impede the downward penetration of the pegs and increase the risk of rot. If the garden soil is heavy, it can be improved with the addition of sand and organic matter to loosen its structure. Raised beds are particularly effective for peanut cultivation, as they warm up more quickly and drain better. A slightly acidic to neutral soil pH between 6.0 and 7.0 is ideal. Before planting, the soil should be worked to a fine tilth, free from large clumps, to allow the pegs to enter easily during growth.
Planting peanuts
To plant peanuts, the seeds should first be removed from their shells. Each pod usually contains two seeds, and these can be sown directly into the prepared soil. The seeds are planted about 5 centimetres deep and spaced 15 to 20 centimetres apart in rows that are 45 to 60 centimetres apart. This spacing allows the plants enough room to spread as they grow, since peanut plants form a bushy habit about 30 to 60 centimetres tall and wide. Covering the seeds lightly with soil and watering gently helps initiate germination, which usually occurs within 7 to 14 days under warm conditions.
Germination and early growth
Once the seeds sprout, peanut seedlings produce small green leaves on slender stems. At this stage, they need consistent warmth and moisture. A sunny, sheltered spot in the garden is best, though in cooler parts of the UK it may be necessary to grow peanuts in a greenhouse or polytunnel to achieve sufficient temperatures. Protecting seedlings from slugs, snails and other pests during the early stages is also important, as young plants are tender and easily damaged. With good care, the seedlings quickly establish themselves and begin to spread.
Flowering and pegging
Peanut plants begin flowering about 30 to 40 days after germination. The small yellow flowers resemble pea blossoms and are self pollinating. After pollination, the flowers fade and form pegs, which are slender stalks that elongate and grow downward into the soil. This is the most unusual part of the peanut life cycle, as the pods develop underground rather than above. For this reason, it is essential that the soil remains loose, friable and free of hard crusts, so that the pegs can penetrate easily. Gardeners often mound soil around the base of the plants during this stage, similar to earthing up potatoes, to encourage pegging and maximise yields.
Watering and feeding
Peanut plants need consistent moisture during germination, flowering and pegging, but they do not tolerate waterlogging. Deep watering that moistens the root zone is better than frequent shallow watering, as it encourages deeper root growth. Once the pods have formed underground, reducing watering slightly can help prevent rot. In terms of feeding, peanuts are legumes and capable of fixing their own nitrogen with the help of root nodules, so they do not require heavy nitrogen fertilisers. Too much nitrogen can actually encourage leafy growth at the expense of pods. Instead, a balanced fertiliser with added potassium and phosphorus supports flowering and pod development.
Pests and diseases
In the UK, peanuts are less likely to suffer from the same range of pests and diseases as they do in their native tropical regions. However, fungal diseases such as powdery mildew can sometimes occur in humid conditions. Good air circulation helps reduce this risk. Aphids and spider mites may attack plants in greenhouses, but these can usually be controlled with natural methods. Protecting pods underground from rodents may be necessary in some gardens, though in most cases pests are not a major problem for small scale peanut growing in Britain.
Harvesting peanuts
Peanuts are usually ready to harvest 120 to 150 days after planting, depending on the variety and growing conditions. In the UK, this often means harvesting in late summer or early autumn. Signs that peanuts are ready include yellowing of the foliage and the plant beginning to die back. To harvest, the entire plant is carefully lifted from the soil, shaking off excess earth to reveal the pods clinging to the roots. The pods should be left to dry, ideally in a warm, airy space, for several days to cure. Once dry, they can be stored in their shells or shelled for immediate use.
Using harvested peanuts
Freshly harvested peanuts can be boiled, roasted or used in a variety of dishes. Homegrown peanuts have a unique flavour and freshness compared to store bought ones. They can also be saved for seed the following season, though they must be kept dry and cool until planting time. Beyond eating, growing peanuts provides an educational experience, especially for children, as it demonstrates how an everyday food develops underground in a way few other crops do.
Growing peanuts in containers
For gardeners without suitable garden beds, peanuts can be grown in large pots or containers. The same soil requirements apply, with sandy, well drained compost being ideal. Containers should be at least 30 centimetres deep to accommodate root and pod development. Growing peanuts in pots allows better control over soil and moisture, and containers can be moved into greenhouses if temperatures drop. However, yields are usually smaller than in open ground, so this method is best for those who want to try peanuts as a novelty rather than a staple crop.
The cultural and historical significance of peanuts
Peanuts originated in South America and have been cultivated for thousands of years. They spread globally through trade and became a vital crop in Africa, Asia and North America. Beyond their value as a food, peanuts play an important role in crop rotation, as they enrich soils with nitrogen through their symbiotic relationship with bacteria. George Washington Carver, a prominent agricultural scientist, famously promoted peanuts in the early twentieth century for their nutritional value and versatility. Today, peanuts remain a major global crop, used in everything from snacks to cooking oils and even industrial products. Growing them in the UK connects gardeners to this rich agricultural heritage, even if only on a small scale.
The challenge of climate in the UK
The biggest challenge for growing peanuts in Britain is the climate. Peanuts require a long, warm growing season, and summers in the UK are often too short and cool for maximum yields. For this reason, peanuts are better suited to greenhouse or polytunnel cultivation in most regions, though some gardeners in southern England may succeed outdoors in warm summers. The relatively low risk of pests in the UK makes up for the climate challenge to some degree, but achieving a large crop requires careful timing, warmth and soil preparation.
Conclusion
So, how do you plant peanuts? The process begins with selecting viable seeds, preparing sandy, well drained soil and planting in warm conditions after the risk of frost has passed. Once established, peanut plants produce yellow flowers that form pegs, which push into the soil and develop into pods. Regular watering, loose soil and careful aftercare support the process until harvest in late summer or autumn. While the UK climate is not ideal, peanuts can still be grown successfully in sheltered gardens or under glass, rewarding the patient gardener with a crop that is both unusual and satisfying. Beyond the harvest, growing peanuts offers insight into the diversity of plants and the ingenuity of nature in producing food beneath the soil.
