How to Grow and Care for Peanut Plants

Ever-popular peanuts are not nuts at all, but the underground seeds of a tropical legume plant related to peas and beans. The peanut plant has a truly unique growing habit. While the yellow flowers traditionally bloom above ground, the fruit and their seeds develop at the end of live shoots called "pegs," which grow down into the ground. The peanut clusters are the fruit that forms at the ends of these pegs.

Peanuts have a long growing season and are most often grown in warmer climates, but you can also try your hand at growing them indoors. These annuals are normally planted from seeds (shelled peanuts) in the spring after the last frost and harvested in the early fall. They require as many as 150 days to produce edible peanuts, but there are early-maturing varieties that require less than 100 frost-free days.

Peanuts are toxic to humans who have peanut allergies.

How to Plant Peanuts

If you live in an area where summers are long and warm with at least 120 to 150 frost-free days, you are in the right location to grow peanuts. For this reason, peanut plants are most productive in USDA hardiness zones 8-11.

When to Plant

Plant after the last frost, sometime in April through May, when soil temps have reached 65°F to 70°F.

Selecting a Planting Site

Choose a site that gets eight hours of full sun per day, and plant in sandy loam soil that drains well.

Spacing, Depth, and Support

Plant the seeds 2 inches deep, 4 to 6 inches apart, and allow 3 feet between the rows. Peanut plants don't need a support structure.

Peanut Care

Light

Peanuts need full sun for at least eight hours per day.

Soil

Peanuts grow best in loose, well-drained, sandy loam with a slightly acidic soil with a pH range of 6.0–6.5. Avoid poorly drained and hard clay soil. Do not plant peanuts in the same space where you have grown other legumes (beans or peas) in previous years.

Water

Peanuts need about 1 inch of rain or irrigation per week during the growing season. Watering is most critical immediately after planting to ensure germination and establishment of the seedlings. Continue consistently watering, especially during the 60 to 110 day period after planting, when the pegs have entered the soil and are filling with peanut clusters. Stop watering the plants 10 days to two weeks before harvesting. Wilting or yellowing leaves mean you're watering the peanut plant too much.

When watering, avoid wetting the leaves and use drip irrigation if possible. The soil should be moist but not saturated.

Temperature and Humidity

The ideal growing temperature for peanuts is between 86°F and 93°F. Higher temperatures may lead to flower damage.

Slightly humid conditions are good while the plants grow, but a period of dry weather is needed before the harvest.

Fertilizer

Peanuts need calcium in the upper 6 inches of the soil where the pods grow. Amendment with bone meal or another source of calcium at the time of planting can help with this.

Peanuts are a legume that fixes its own nitrogen in the soil if rhizobium bacteria are present. Therefore, peanuts do not need additional nitrogen fertilizer. However, if you plant them in a location where peanuts have never been grown before, it might be a good idea to add a peanut inoculant to the soil at the time of planting, which stimulates the roots to grow the nodules that fix nitrogen in the soil.

Note that peanuts are extremely susceptible to fertilizer burn, so if you do feed, do so before seeding and make sure to thoroughly work any fertilizer into the soil.

Adding a Peanut Inoculant

A peanut inoculant is a powder, liquid, or granular product that contains a bacterium, called Bradyrhizobium. The bacteria enhance nitrogen in the soil through a chemical reaction in the peanut plant's roots. Using a peanut inoculant correctly means the peanut plants will reap a healthy, abundant crop.

Pollination

Peanuts self-pollinate and do not rely on pollinators to carry pollen from one plant to another to reproduce. When plants are about 18 inches high, they produce flowers, which occurs about 40 days after planting. From the flower's ovary, the plant sends down a fruiting "peg," which will penetrate the soil, then turn sideways to begin its transformation into a pod with seeds inside. Within four to five months of planting, each individual plant may "peg" as many as 40 pods.

Types of Peanuts

• Valencia peanuts are the quickest to mature in 90 to 110 days. It is therefore often the variety preferred by home gardeners. They have three to five relatively small kernels per pod, with pretty red seed coats.
• Spanish peanuts take 90 to 120 days to mature. The peanuts are mainly used for candy and roasted peanuts.
• Virginia peanuts and runner peanuts both require about 130 to 150 days to mature. This variety produces a high yield of large pods. As their name indicates, runner peanuts need more space, about 3.5 feet per plant. The fruit is small, with two kernels per pod. They have excellent flavor and are most commonly used for peanut butter. Both Virginia and runner peanuts are intolerant of cool temperatures and drought.

Harvesting Peanuts

Several signs will tell you that peanuts are ready to be harvested in late summer or early fall. The most obvious is yellowed foliage, but you should also pull a couple of pods from the ground and inspect them carefully. Ready-to-harvest pods have the typical veined surface, the seed coats are colored, and most of the pods have a darkened inside surface. When you harvest the peanuts, the soil must be dry.

1. Dig or pull the entire plant from the ground and gently shake it to remove excess soil.
2. Hang the plants with the peanuts attached in a dry, warm location with good air circulation.
3. Leave them to cure for about one week.
4. After curing, shake the soil from the pods.
5. Remove the peanuts from the vines.
6. Continue to air-­dry the peanuts for another week or two.

Tip

A peanut plant generally produces between 30-40 nuts, and each pod should contain two peanuts.

How to Grow Peanuts in Pots

Peanuts can grow in pots that are 18 to 20 inches wide and 18 inches deep for one plant. Peanuts need a pot deep enough for pegs to grow beneath the soil, and it should have drainage holes.

How to Grow Peanuts From Seeds

Shelling ordinary raw, uncooked peanuts gives you the seeds necessary to grow peanuts. Raw grocery peanuts can work for this, though it's better to buy your seed peanuts from a garden center.

1. Sow seeds directly outdoors after the last frost.
2. Remove the seeds from their shells before sowing. But be very careful not to remove or damage the tender skin on the seeds, or the seeds won't germinate.
3. Plant the seeds 1 to 2 inches deep, 4 to 6 inches apart.
4. Leave 3 feet between the rows.
5. Keep the soil moist to ensure germination.
6. Seeds will germinate in 10 to 15 days.
7. Thin the seedlings when they are about 2 inches tall, to a spacing of 8 to 12 inches.
8. As the plants grow to about a foot tall, "hill" them by heaping additional soil around the base of the stem, along with light mulch for weed control. The hill accommodates the peg. Keeping the area around the peanut plants weed-free and loose is very important to produce healthy pegs.
9. Pegs grow from the faded flowers and push into the soil about 1 to 3 inches.
10. After the pegs have entered the soil, do not disturb them. You might see lots of flowers on the plants but only 15 percent of them will actually send a peg into the soil and grow peanuts.

Potting and Repotting

Fill a pot with potting mix, plant three seeds in the middle, and water to moisten the planting area. The pot should be 18 to 20 inches wide by 18 inches deep with drainage holes. Place in a spot with full sun and water so the soil is consistently moist but not saturated. When the seedlings reach 4 to 6 inches, pick the healthiest plant and thin out the other two. Since peanuts are grown as annuals, they will need to be replanted each spring.

Common Pests & Plant Diseases

Peanuts can be affected by a wide range of pests and diseases, especially hungry squirrels, mice, and chipmunks (secured mesh row covers can help here). Leaf-feeding insects may include armyworms and caterpillars. Common diseases are leaf spot, rust, blight, and viral diseases. To help identify what is harming the plants, seek assistance from your local university extension office. They will also suggest the best remedies for the ailments.

From: thespruce