Peanuts are a unique crop that develops its fruit beneath the soil, making them a rewarding challenge for the home gardener. These legumes require a long, warm growing season, typically spanning 120 to 140 frost-free days. Understanding the specific needs of the peanut plant, from soil preparation to its distinctive growth process, is the foundation for a successful harvest.
Preparing the Planting Site
Peanuts thrive in full, direct sunlight for at least eight hours daily. Soil composition is important because the fruit develops underground, requiring a loose, well-drained medium for proper pod formation. Sandy loam is ideal, and heavy clay soils should be amended with compost or sand to improve texture and permeability.
The soil must be sufficiently warm before planting, as peanuts are sensitive to cool temperatures. Wait until the soil temperature consistently reaches 65°F, usually in late spring or early summer after the last frost. A slightly acidic soil pH, ideally between 6.0 and 6.5, supports healthy growth. Peanuts are nitrogen-fixing legumes, so they generally do not need high-nitrogen fertilizers, but a soil test can determine if calcium or other amendments are needed.
Step-by-Step Seed Planting
Begin by selecting raw, unroasted peanut seeds and gently shelling them just before planting. The thin, papery skin surrounding the seed must be kept intact, as damaging it can inhibit germination. Soaking the seeds is not recommended, as it can make them susceptible to rot.
Once the soil is warm, plant the shelled seeds 1 to 2 inches deep. Space the seeds approximately 6 inches apart within rows for optimal growth and air circulation. Rows should be spaced 2 to 3 feet apart to allow room for the plants to spread and for the later hilling process. Provide a thorough initial watering and keep the seeds consistently moist until germination, which typically occurs within 10 to 15 days.
Managing the Unique Peanut Growth Cycle
Peanut plants have a unique growth habit where the flowering and fruiting stages are separated. About 30 to 40 days after planting, the plant produces small, yellow, pea-like flowers above ground. Once a flower is pollinated, its petals drop, and the fertilized ovary begins to elongate into a specialized structure called a “peg.”
This peg is a stalk that grows downward, pushing its way into the loose soil about 1 to 2 inches deep. The peanut pod then develops at the tip of this underground peg. Because the pod forms beneath the surface, the soil must remain light and free of hard clumps. Gardeners should begin “hilling” as soon as the first flowers appear, which involves mounding loose soil around the base of the plant. This action ensures the developing pegs have an easy path to penetrate the earth, allowing the pods to successfully form and mature.
Consistent moisture is important during the 60 to 110-day period after planting, which is when the majority of pegging and pod filling occurs. Peanuts require about one inch of water per week during this phase to support underground development. Keeping the area around the plants weed-free is important, but avoid deep cultivation or weeding that could damage the delicate, shallow-forming pegs and developing pods.
Knowing When to Harvest
Peanuts typically require 120 to 140 days to reach full maturity, depending on the variety and local climate. The most reliable visual indicator that the crop is ready for harvest is when the plant’s leaves begin to yellow and wither, signaling the end of the growth cycle. Stop watering the plants approximately 10 days to two weeks before the expected harvest date, which helps to dry the soil.
To check for maturity, carefully dig up a single test plant and inspect the pods. Mature pods should be fully filled, and the inner shell lining should be dark in color. When ready, use a garden fork to carefully loosen the soil around the plants before gently pulling up the entire plant. Shake off any excess soil and leave the entire plant, with the peanuts still attached, to dry and cure.
Curing is a necessary step that reduces the moisture content of the nuts from a high of 35 to 50 percent down to 8 to 10 percent. This process prevents mold and spoilage while concentrating the flavor. Hang the entire plants in a warm, dry, and well-ventilated area, such as a garage or shed, for one to two weeks. After this initial drying, remove the pods from the vines and spread them in a single layer to continue curing for an additional one to two weeks before storage or consumption.