Days to germination: 3 to 5 days
Days to harvest: 130 to 140 days
Light requirements: Full sun
Water requirements: Frequent watering
Soil: Sandy and well-drained
Container: Possible with a fairly wide container
Peanuts are fairly unique in the nut world, as they grow underground and are not produced by large trees. That’s because they are not actually nuts at all, but legumes like beans or peas.
Once called goober peas in the United States, peanuts are a very popular snack food. They are most often eaten roasted on their own, as opposed to many other nuts that are used more in cooking. They are easily shelled by hand, which adds to their appeal.
There are two different kinds of peanut plants, one that grows in an upright bush and one that grows as a runner. Most home gardeners plant the bush type as it is much easier to harvest. Virginia varieties usually produce large peanuts with 2 kernels in each shell, whereas Spanish peanuts are smaller but usually have 3 nuts in each shell. If your growing season is not quite long enough, you could try Valencia peanuts. They mature in around 100 days.
Peanuts are very high in protein, more than other legumes or nuts. They also have fiber, magnesium, zinc and vitamin E. Unfortunately, there is a relatively high incidence of peanut allergies these days which has put the peanut slightly out of favor with the general populous.
Starting from Seed
Though some have had good success just planting peanuts bought at the grocery store (the raw ones, not roasted), you will do better getting proper seed peanuts from a gardening center. Purchased peanut seed should still be in their shells. You will have to shell them right before planting or they will dry out and not germinate.
Given their long growing season, you may want to get your peanut plants started early indoors. Use paper or peat pots so that you don’t shock the roots anymore than necessary, peanuts are quite delicate when it comes to transplanting.
Start your seeds 3 or 4 weeks before you expect your last frost date. Keep them well watered, but don’t soak them.
Your peanuts should be planted about 10 inches apart, with 2 or 3 seeds at each spot. They should be covered with 2 inches of soil. Once they sprout, thin it down to just 1 sturdy plant every 10 inches. Your peanuts or seedlings should be planted when there is no more threat of frost, about a week or two after your expected frost date.
Dig your soil down at least 6 inches to loose in it up for the growing peanut roots. Add a little extra lime to the soil to balance the pH.
As it grows, your peanut plant will put out runners, and each one will eventually grow a peanut at the end underground. These runners start out as the above-ground flowers. So once you see the plant’s flower starting to wilt and bend down, do not pick them off. That’s where your peanuts are going to come from. Those downward growing stems are called “pegs”
When you see your plants starting to grow their pegs, lightly dig around the plants so that the soil is very loose. The peg needs to grow down underground so you don’t want it blocked by stones or packed soil.
Once your plant has set down its pegs, do not cultivate or weed to roughly around the plant or you could accidentally pull up or break off a runner. Mulching can help keep the weeds down, just don’t add mulch until the pegs have moved down into the soil.
You will want to water your plants frequently, but avoid giving them too much water at once. Fertilizing is fine though not necessary. Use a low-nitrogen formula or you will end up with very bushy plants and no peanuts. When the plants begin to flower, a treatment with a calcium-rich fertilizer can help with nut formation.
Peanuts can be grown in containers, but you need to allow for extra surface space for the pegs to be put down by the plant. Your peanuts should be in pots no smaller than 20 inches across and at least a foot deep. Just one plant per pot.
Keep your plants well-watered but take care not to let the roots get waterlogged. Your containers should drain well.
Pests and Diseases
Peanuts are not really subject to many insect or disease problems.
Any usual garden insects that eat leaves can do damage to your peanut plants, such as cutworms or cucumber beetles. Spray the leaves of your plants with a pyrethrin-based insecticide spray to keep the bugs away. Watch for aphids too.
You will probably have more problems with mice or squirrels than any insect pests. They will dig up your peanuts once the pegs have set and the nuts begin to form. You might have to put some wire fencing around your plants to protect them, and make sure to push the fencing several inches below the soil to stop any digging.
Harvest and Storage
A healthy peanut plant will yield between 30 and 50 peanuts at harvest time.
Peanuts are sensitive to frost. Try to harvest your plants before the first fall frost, or immediately afterwards. Because peanuts don’t set their pegs all at once, you can have various levels of maturity among your peanuts. Don’t be surprised if some pods are not usable when you pull up your plants. Waiting longer can help a few more mature, but you may run the risk of frost damage if you wait too long.
When the peanuts are ready, the plant will start to yellow and wilt. Pull up the entire plant, and hang in a warm place for 1 to 2 weeks to let the peanuts cure. You can pull the nuts off the plant at this point, and then let them continue drying for another 2 weeks.
After that, you can roast them for eating or store them. For storage, leave your peanuts in their shells. They will last up to 6 months in the fridge that way. You can also freeze them, and they will last upwards of a year. For larger crops that won’t fit in the refrigerator, store the raw peanuts in their shells in a well-ventilated place that is both dry and dark. They are fine for 3 months.
If you discover your nuts have gotten moldy, you should dispose of them immediately. The aspergillus fungus can grow in moist conditions, and produces aflatoxin which is toxic in humans.