Peanuts are a tropical legume. Growing them is fun and rewarding. And watching the peanuts grow is fascinating too, especially with kids because peanuts are unique in their growing habit. The plants send shoots called “pegs” into the ground where the peanut clusters grow.
|Botanical Name||Arachis hypogaea|
|Common Name||Peanuts, Goobers, Groundpeas, Ground nuts, Earth nuts|
|Mature Size||1 to 2 feet with a three-foot spread|
|Sun Exposure||Full sun|
|Soil Type||Sandy loam|
|Soil pH||6.0 to 6.5|
|Hardiness Zone||Zones 5-7 ("Northern" varieties) 8-12|
|Native Area||South America|
How to Grow 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.
Peanuts needs full sun for at least eight hours per day.
Peanuts grow best in loose, well-drained, sandy loam. 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.
Peanuts need about one inch of rain or irrigation per week during the growing season, specifically after planting to ensure germination and establishment of the seedlings; then 60 to 110 days after planting when the pegs have entered the soil and up to the time when the pods have filled.
Stop watering the plants ten days to two weeks before harvesting.
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 and 93 degrees 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.
Peanuts need calcium in the upper six inches of the soil where the pods grow.
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 make sure to always thoroughly work any fertilizer into the soil before seeding.
Growing Peanuts From Seeds
Sow seeds directly outdoors after the last frost. Remove the shells before sowing but be careful not to damage the tender skin on the seeds. Plant the seeds one to two inches deep, four to six inches apart. Leave three feet between the rows. Keep the soil moist to ensure germination. Seeds will germinate in ten to 15 days. Thin the seedlings when they are about two inches tall, to eight to 12 inches between each plant.
Keeping the area around the plants weed-free and loose is very important because once the plant has flowered and has been pollinated, it will start sending pegs into the soil. Adding a couple of inches of mulch helps with weed control.
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.
Growing Peanuts in Containers
The limited soil space of a container would lead to a poor harvest, therefore growing peanuts in containers is not recommended.
There is a number of signs that 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 if the 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. Dig or pull the entire plants from the ground and gently shake it to remove excess soil.
Hang the plants with the peanuts attached in a dry, warm location with good air circulation. Leave them to cure for about one week.
After curing, shake the soil from the pods. Remove the peanuts from the vines and continue to air-dry the peanuts for another week or two.
- Valencia peanuts are the quickest to mature in 90 to 110 days. It is therefore often the variety of choice for home gardeners. They have three to five relatively small kernels per pod, pretty red seed coats.
- Spanish peanuts take 90 to 120 days to mature. The peanuts are mainly used for candy and as 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 with excellent flavor.
- 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 won’t tolerate cool temperatures or drought.
Peanuts can be affected by a wide range of pests and diseases. Leaf-feeding insects may include army worms and caterpillars. Common diseases are leaf spot, rust, blight, and viral diseases.
As with all pests and diseases, before any type of treatment, make sure to properly identify what is harming the plants by seeking help from your location Extension Office.
Some diseases can be managed by choosing less susceptible varieties.