How to Grow Peanuts

However, peanuts do not look like most regular nuts - and there is a good reason for that. This is because peanuts are fairly unique in the nut world, as they grow underground and - unlike most other nut varieties - are not produced by large trees.
Peanuts are a native to South America and are believed to have first been cultivated as a farmed crop in the valleys of Peru. To be fair though, peanuts are not what we would consider to be a true nut, but are in fact legumes - the pea family. This then really does make it a pea nut!

What is a peanut?

The peanut is a small annual herbaceous plant that grows to 30-40 cm tall. It produces a typical peaflower flower which is usually yellow with reddish veining.

Weirdly, once pollinated the flower stalk will begin to bend until the fertilized ovary touches the ground. However, the stalk continues to grow and pushes the ovary underground! The ovary continues to develop into a legume pod which matures into what we commonly call a peanut. Each pod can be between 1-3 inches long and containing as many as 4 ‘seeds’.

How to grow peanuts:

While you can have some good success by planting peanuts bought at the grocery store -  raw ones, not roasted, you will do far better by purchasing proper seed peanuts from a good plant retailer. Purchased peanut seed should still be in their shells, but you will have to shell them immediately before planting or they may dry out to  a point where they will not germinate.

Given their long growing season, you may want to get your peanut plants started early indoors. Use paper or peat pots as can reduce root shock when it comes to transplanting. You will need pots that are 3-4 inches in diameter so if you cant find biodegradable pots at this size them use plastic instead.

Start your seeds 3 or 4 weeks before you expect your last frost date. Using a good quality compost such as John Innes 'Seed and Potting' , plant 2 or 3 seeds in each pot, and  covered them with 2 inches of compost soil. Keep them well watered, but don’t have the compost waterlogged as this will damage the juvenile root system.

Once the peanut seeds begin to germinate, remove the weakest leaving just one strong peanut plant per pot. Your peanuts or seedlings should be planted outside into their final position once there is no more threat of frost.

Planting peanuts outside:

Dig your soil down at least 6 inches to loose in it up for the growing peanut roots. You may need to add a little extra lime to the soil to balance the pH, but this should only be done once a soil test has confirmed that this is necessary.

As it grows, your peanut plant will produce 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 the next generation of peanuts will be produced. Those downward growing stems are commonly known as “pegs”

When you see your plants starting to grow their pegs, lightly dig around the plants in order to loosen up the soil. The peg needs to grow down underground so you don’t want it blocked by stones or compacted 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, but do not 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 really 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.

Growing peanuts in containers: 

Peanuts can be grown to harvest 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. You can only have one plant per pot.

Keep your plants well-watered but take care not to let the roots get waterlogged. It is important that your containers are well drained.