Growing your own “baby peanut plant,” Arachis hypogaea, offers a unique gardening experience. These plants, distinct from typical garden vegetables, are a rewarding project for home growers.
The Peanut Plant’s Unique Growth
The peanut plant, Arachis hypogaea, is a legume, like peas and beans. Like other legumes, peanuts fix nitrogen, improving soil fertility. However, peanuts have a distinctive growth habit called geocarpy.
Geocarpy involves the plant flowering above ground, but developing its fruit beneath the soil. After pollination, yellow flowers wither, and a specialized stalk, called a “peg” or gynophore, emerges. This peg elongates, pushing the fertilized ovary into the soil. Once underground, the peg’s tip swells, and the peanut pod forms and matures. This subterranean development protects the developing peanuts from environmental stressors and predators, ensuring a suitable environment for the offspring.
Growing Peanut Plants from Seed
Cultivate peanuts from raw, unroasted, unshelled seeds; roasted or boiled peanuts will not germinate. Peanuts thrive in loose, well-drained, sandy loam soil with a slightly acidic pH (6.0-6.5). Avoid heavy clay soils, as they hinder the pegging process.
Plant seeds outdoors after the last frost when soil temperatures consistently reach 65°F to 70°F at a 4-inch depth. For cooler climates, start seeds indoors three to four weeks before the last frost. Plant seeds 1 to 2 inches deep and 4 to 6 inches apart in rows spaced 3 feet apart. Consistent moisture after planting promotes germination, which typically occurs within 7 to 15 days.
Caring for Your Peanut Plant
Peanut plants require full sun exposure, at least 8 hours daily. Consistent moisture is important, with plants needing about 1 inch of water per week. Watering is crucial when pegs enter the soil and pods develop (60-110 days after planting). Avoid overwatering, as this can lead to yellowing leaves.
As legumes, peanuts fix their own nitrogen, reducing the need for nitrogen fertilizers. They benefit from calcium in the upper 6 inches of soil where pods form. Applying bone meal or another calcium source at planting is beneficial. When plants reach about a foot tall, hilling them by mounding loose soil around the stems encourages more pegs to penetrate the soil, leading to a larger yield.
Harvesting Your Peanuts
Peanuts are typically ready for harvest between 120 and 160 days after planting, depending on the variety. A primary indicator that peanuts are ready is when the plant’s leaves begin to yellow and wither. Before harvesting the entire crop, dig up a single test plant to inspect the pods. Mature pods should be well-filled, with the inner surface of the pod often darkening.
Harvesting should occur when the soil is relatively dry. Loosen the soil around the plants with a garden fork or spade, then gently pull up the entire plant, ensuring the pods remain attached and shaking off any loose soil. After harvesting, the peanuts need to be cured, a process of drying that reduces moisture content and enhances flavor. Hang the entire plants with peanuts attached in a warm, dry, well-ventilated area away from direct sunlight for about one to two weeks. After this initial drying, remove the pods from the plants and spread them in a single layer in a cool, dry place for an additional two to three weeks to complete the curing process.