How to Grow Peanuts

Starting Peanuts Indoors

Know the benefits of starting a peanut plant indoors. Peanuts have a long growing season and require 100 to 130 frost-free days to reach maturity. If you live in a cooler, Northern region, you should start the plants indoors roughly one month before the last anticipated frost. If you live in a warmer, Southern region, you can either plant the peanuts directly outdoors after the last frost or start them indoors a few weeks prior to the last frost.

Pick out good seed peanuts. You can plant raw peanuts purchased at the grocery store, but you might find it easier to grow peanuts if you start with seed peanuts purchased from a gardening store. Note that peanuts used as seeds must remain in their shells until just before planting. Otherwise, they will dry out too quickly and will fail to produce. Never use roasted peanuts. These will not germinate.

Fill a clean container with moist potting soil. Use a bowl or starter pot roughly 4 inches (10 cm) deep and fill it about 2/3 full with potting soil. If the soil is not already damp, moisten it with a watering can now, before you add the seed peanuts. The safest container to use would be a paper or peat pot since you can place the entire seedling, pot and all, into the ground when transplanting. You could use a plastic bowl or pot if that is your only alternative, though. Make sure that container is clean before you plant the peanuts, especially if you are using a plastic container. Wash it with warm water and soap, rinse well, and dry with clean paper towels.

Place a few seed peanuts on top of the soil and cover. Arrange four peanuts, with their shells removed, equidistant from each other on top of the soil, pressing them gently into the soil. Cover with roughly 1 inch (2.5 cm) of loose, moist soil. When shelling the peanuts, make sure that you do not remove the brown paper coating surrounding each nut seed. If you remove this or damage it, the peanuts may not germinate. You could plant the peanuts without removing the shell first, but they will grow quicker if you do remove the shell. If the soil is not moist when you add it, lightly water it with a watering can or spray bottle until it is moist to the touch but not soaked. If planting the seeds directly outside, plant them 2 inches (5 cm) deep and 8 inches (20 cm) apart.

Transplanting Peanut Plants

Choose a sunny location. Peanut plants require full sun in order to grow properly. Sun is important for the sake of photosynthesis, but full sun is advised because areas that receive full sun are likely to be the warmest in your garden. Peanut plants thrive in warm soil.

Wait until after the last frost passes. Peanuts are fairly sensitive to frosts, so you should wait at least two to three weeks after the last suspected frost before you transplant any seedlings started indoors an outdoor garden. The same guideline applies if you are planting seed peanuts directly into an outdoor plot. Wait several weeks after the last frost passes. Otherwise, the seed peanuts will not germinate. The temperature of the soil should be about 65 degrees Fahrenheit (18.3 degrees Celsius), at minimum.

Improve the soil quality, if necessary. The plant bed should be composed of loose, well-drained soil. If your soil is too heavy, you should add a few handfuls of sand to the soil to improve the quality and make it less dense. Dig and mix the sand in with a small trowel. Avoid clay-type soils, which are hard to improve sufficiently. You could use aged compost, as well, but you should limit the amount you use since it could give off nitrogen. This would be beneficial for many plants, but peanuts produce their own nitrogen, and adding more can be too much and ultimately stunt the growth of the plant. You may also need to balance the soil pH if it is too acidic. Do so by adding a small amount of agricultural lime to the soil and mixing it in thoroughly.

Dig deep into the soil. Dig at least 6 inches (15.24 cm) down into the soil, even if the plant is not yet that deep. The roots need plenty of room to spread out. Digging into the soil helps to break up any compact areas, ultimately making it looser, and providing the roots the space they need. After digging into the soil, fill in the bottom of each hole with 2 inches (5 cm) or so of the loose soil. Otherwise, you may accidentally plant the seedling too deep.

Plant the seedlings 10 inches (25 cm) apart. The stem and leaf portions should be above the ground, but the root system should be completely below ground. Fill in the rest of the hole gently with loose soil. If using a decomposable planter, place the entire thing in the ground. If not, gently squeeze the sides of you container to loosen its contents. Tip the container so that the plant, roots, and soil come out in a clump in your hands. Transfer the entire clump to the outdoor plot. Avoid exposing the sensitive roots. If you planted the seed peanuts directly outdoors, you may decide to plant 2 to 3 seeds at each spot initially. You will need to thin the plants out, though, leaving only the strongest one at each spot.

Water the soil well. Use a gentle hose or watering can to moisten the soil so that it feels moist when you touch the surface. Note, however, that the soil should not be soaking wet. If puddles are forming on the surface of the plot, you may have added too much water.

Daily Care

Loosen the soil after a few weeks. Once your plants reach a height of 6 inches (15.24 cm), you should lightly and carefully dig around the base of each plant to loosen the soil. The plant will develop runners as it grows, and each of these runners will develop blossoms. The flowers will wilt and bend down, but you should not pick them off. These downward stems are called "pegs." Your peanuts will grow off of these pegs, and the stems need to find their way underground in order to grow those peanuts. By making the soil looser, you make it easier for the pegs to get underground.

Hill the soil around the base of the plant later on. After the pegs have found their way underground and the plants themselves are about 12 inches (30.5 cm) tall, you should gently form the soil into small hills around each buried peg and around the base of the plant. Doing this provides extra warmth and protection for the peanuts growing on the ends of the buried pegs.

Lay down a light mulch. Spread out 2 inches (5 cm) of straw or grass clippings over the area immediately after creating the hills. Mulch prevents most weeds from coming up. Additionally, it also keeps the soil warm, moist, and soft. Do not use heavy mulches like wood chips, though. Additional pegs may need to break through the soil, and they will not be able to do so with heavy mulches in the way.

Water regularly. Use a watering can or garden hose with a gentle spray setting to provide the plants with 1 inch (2.5 cm) of water each week. Ideally, peanuts should be given a little water at a time. They do best when the soil is slightly dry on the surface but moist at about 1 inch (2.5 cm) down. This can be determined by sticking your fingertip into the soil and noting how much of your finger you can insert into the soil before you feel moisture.

Avoid fertilizers with high levels of nitrogen. Fertilizers are not usually necessary to begin with when growing peanuts, but if you do opt to use a fertilizer, make sure that it does not contain large amounts of nitrogen. Peanuts supply their own nitrogen. Adding more nitrogen to this will produce very bushy plants with thick foliage and little fruit yield. Once the plants begin to flower, you can begin treating them with a fertilizer rich in calcium. Doing so may help maximize nut formation.

Protect your plants with mesh fencing. The biggest threat to your peanut plants are squirrels, chipmunks, and other small critters looking for a free feast. Placing mesh fencing around your plants is a simple, sure way to keep these uninvited dinner guests out of your crop. Push the fencing 2 to 3 inches (5 to 7.6 cm) below the ground to protect the peanuts as they grow underneath. Many mice and squirrels will try to dig the plants up after nuts begin forming, and if the netting does not extend below ground, they may succeed.

Use insecticide only as needed. Peanut plants are not usually victims when it comes to pests of the insect variety. Some insects do occasionally make themselves a nuisance, though, including cutworms, cucumber beetles, and aphids. These insects usually attack by eating the plants. Spray the leaves with a pyrethrin-based pesticide for best results. If you want to stick to something organic, sprinkle ground red pepper on the leaves, instead.

Harvest and Storage

Dig out the entire plant with a spading fork. You should harvest the peanuts before the first frost of fall occurs, since peanuts at this stage are still sensitive to frost attacks. The plant will turn yellow and begin to wilt when it is ready to be harvested. Gently dig up the entire plant with your gardening fork, lifting it up from beneath the roots. Shake off most of the soil clinging to the roots. A healthy plant will usually yield about 30 to 50 peanuts.

Dry the plant out. Hang the plant indoors in a dry location for about a month. For the first one to two weeks, let the peanuts cure on the plant as they are in a warm, dry spot. For the remaining two weeks or so, pull the nuts off and let them dry in the same warm, dry spot.

Roast or store the plants as desired. You can enjoy the peanuts raw or roasted, or you can save them for later. To roast peanuts, bake them in an oven set at 350 degrees Fahrenheit (177 degrees Celsius) for 20 minutes. To store peanuts, leave them in their shells and place them in an airtight container in the refrigerator up to 6 months. If you cannot refrigerate your peanuts, they can stay good for 3 months in a dry, dark storage area. Peanuts can also be frozen for a year or longer.