Are Peanut Shells Good for Compost?

Today it’s more common to grab a snack of nuts and fruit than it is to scarf down a whole meal, and among these on-the-go meals, peanuts reign supreme. While technically a legume and not a nut, the structure, taste, and shell of peanuts are similar to tree nuts, and so it is generally categorized as the same, at least at the grocery store anyway. When indulging in a snack of peanuts, there is sometimes the question of what to do with the shell when you are done.

The compost pile is the obvious choice, as peanuts are food, and edible things are always biodegradable. The only things not recommended in compost are heavy fats and meats that will go rancid and attract pests. Peanuts have a high oil content but will it lead to the same problems in a compost heap? Let’s find out! 

Can Peanut Shells be Composted?

Peanuts – the plants, the shells, and the skin – can all be composted with no risks to the compost. Peanut shells add carbon and micronutrients that improve soil and feed plants. Disposing of peanut shells in the compost pile can increase moisture retention and feed microbes for longer. 

Like other shells, peanut shells take several months to break down and can clump together if added all at once and not mixed well. Peanuts also are often salted and can kill off beneficial soil microbes if excess salt is added all at once. Stagger adding salty peanut shells to your pile with plenty of other kitchen scraps, or rinse the salt off before adding to optimize the composting process. 

How to Compost Peanut Shells

Like other shells taking a bit of time to properly prepare peanuts can increase the speed shells in compost decompose. Without treatment, piles of harder food scraps can take 6 months to a year to break down in a compost pile or compost bin. Some old or soggy shells may contain fungal disease, so dispose of these where they won’t contaminate garden soil. 

Gather and Crush

Compost ingredients work better when they are added in a large amount at once. Having more material will create more heat and invite more composting organisms to feast. Make sure that the shells are stored somewhere dry to make sure they do not start to rot before you are ready to add them to the kitchen compost, and then crush them small when ready to use them.

Rinse and Soak

A healthy compost pile can handle a bit of salt and other non-ideal compost ingredients without too many negative issues. Too much salt can damage plants and stunt the growth of garden plants when add to the soil. To remove extra salt, rinse the shells once and then soak them for at least 12 hours to prepare for composting. 

Mix with Browns and Greens

Organic fertilizers can work better than chemical fertilizers, but only if the correct mix of green and brown ingredients is added for a balanced, nutrient-rich compost. Shells are brown, so you will need to add more green compost ingredients, like veggie scraps, for quality compost. Other brown materials like cardboard should be mixed with the peanuts shells to give a higher ratio of carbon to nitrogen. 

Layer in Compost

Layering compost by material helps worms and other compost critters to navigate through and create better soil. Brown materials dry out quickly and need more water more often, whereas green materials can become anaerobic and end up too wet. Combining the two into layers helps create a better environment for a faster decomposition time. 

Mix and Distribute

When you add a bunch of shells to the pile, you will want to mix them into the rest of the organic waste. Doing this will help the pieces find solitary areas where the microbes can surround and quickly break down the shells. Material sprinkled on top of a compost pile will take far longer to break down than pieces buried inside. 

Wet and Turn 

Shells and other dry materials will dry out with airflow and sunlight. The more sunlight and wind, the faster the pile will need water, and the sooner you will have to soak the materials. Make sure to turn the pile regularly to speed up processing time and reduce odors and other compost issues. 

Benefits of Composting Peanut Shells?

Peanut Shells in Compost

There are tons of reasons to compost peanut shells in addition to the obvious reducing landfill waste. Taking a look at all the advantages your soil gains when carbon elements like peanuts are added can help you overlook the extra steps needed to add them. The most notable benefits are: 

Increase Carbon

Adding carbon content to compost is one of the quickest ways to build soil and benefit the environment. Other carbon materials like paper and boxes can be added with shells to increase the carbon-to-nitrogen ratio and promote bacterial population growth. During winter months, it can be hard to get enough carbon, so peanut shells are a great addition. 

Improve Compost Structure

Dry carbon ingredients can also improve the soil structure of compost. When green materials get wet, they compact but shells and other brown matter can hold their shape and leaves air pockets and places for bacteria to flourish. Mix shells thoroughly into the pile to promote better compost structure. 

Longterm Food for Microbes

Some materials, like grass clippings, break down very quickly and provide very little food for microbes. Peanut shells and other brown materials are slower to decompose and can last for months in the soil. While they are still there, microbes can live off of them, and the population can expand, ready to ingest new food and compost materials as they are added. 

Moisture Retention

Clumps of brown materials inside of a compost pile can hold moisture longer than soil alone. If the material is soaked well, it will retain the moisture longer and help roots deep underground have access to water when surface conditions are hot and dry. Shells on the surface will wick moisture and should be covered with soil or wet materials to avoid drying out the entire pile. 

Naturally Decomposing

Unlike trash in landfills, peanuts will decay on their own and leave no trace but enriched soil for your garden plants. Wet and crushed shells will break down much faster than whole dry shells. Add green materials to supercharge the decomposition process for peanut shells. 

Other Uses for Peanut Shells 

If you don’t have a compost pile or you can’t toss your peanut shells in there for whatever reason, do not fret. There are still other ways to use your shells that keep them out of the trash and help your lawn and garden. Check out some additional ways to use peanut shells below. 

MulchLay out around plants and trees 1 to 3 inches thickLocks in moisture and helps protect roots from temperature extremes 
Potting Soil AdditiveCrush and mix with potting soil before planting Add natural fertilizer and increase soil structure and moisture retention in the soil
Pest Deterrent Place whole crushed shells around vulnerable plantsStops snails, slugs, and soft-bodied insects from getting to your plants
Squirrel DecoyLeave uncrushed shells near bird feeders and other common squirrel areasSquirrels will search for nuts in the empty shells and leave bird feeders alone for a while


Placing shells as much is the simplest way to dispose of this food waste. Dump them around plants in a layer at least 1 to 3 inches thick. The thicker the layer, the more benefits your plants will derive from the mulch. Moisture retention and root protection are two of the main reasons to mulch with peanut shells. 

Potting Soil Additive

Adding supplements to your potting soil can improve the structure and capabilities to help your plants thrive out of the ground. Little bits of peanut shell mixed in with soil can create pockets of moisture retention that improve aeration and root health. Microbes will also enjoy the availability of organic matter and feed on it for many months. 

Pest Deterrent 

Snails and slugs will crawl along the ground, find your plants and eat the leaves. They can cause a lot of damage, considering how slow they move. Crushed-up shells on the ground around your plants will repel these pests and keep your pants safe with no chemicals needed. 

Squirrel Decoy

Squirrels love to steal food from your yard. Whether garden plants or bird feeders, they will try to take what they can. Whole empty peanut shells near the areas squirrels forage and hang out can distract them while they look for nuts to no avail. This is a good temporary measure to give the birds time to use the feeders before the squirrels scare them off.