16 Food Scraps That Can Be Used To Fertilize Your Garden

While we often love the taste of food and need it to survive, we also dump billions of dollars worth of food into the trash annually. In fact, it's estimated that, in the U.S., waste that could add up to 68 million meals is being thrown away each year. That's a lot of wholesome goodness that could be redirected, recycled, and reused as fertilizers in our gardens. Fertilizers come in all shapes and forms, but their sole purpose is to provide plants with the chemical elements they need to survive and thrive.

Although synthetic fertilizers contain the same nutrients as natural types, their quick-fix formula means they provide less nourishment for your soil, whereas organic fertilizers act slower and are the gift that keeps on giving. In the average household, there's a whole host of food scraps that end up in the waste bin. A lot of these could be used to make your garden a healthier, happier, more organic, and more productive place. So the next time you peel that banana, chop that onion, crack those eggs, or boil those vegetables, stop and consider how beneficial the waste product could be for your soil. Not only could you help save the planet, but you could also save yourself a few bucks. You'd also be surprised how effective food scraps can be as a fertilizer in your garden.

Bananas are loaded with potassium, magnesium, vitamin B6, vitamin C, and a potent assortment of antioxidants. Yet it's not just your body that can benefit from the properties of this super fruit. When you've had your fill of its flavor, you can throw the inedible banana peels on an existing compost pile, plant them in some soil, or ferment them in a little water to create a spray fertilizer. The potassium, calcium, magnesium, and phosphorus in banana peels can improve nutrient distribution in your plants, improve root growth, and strengthen the stems.

To make a fertilizer slurry, soak your banana peels in some water before blending them in a food processor. Then dig a shallow hole to place the slurry near your plants. To make a spray fertilizer that is rich in nutrients and great at repelling bugs, soak the peels in water for seven days or more, depending on how acidic you want the fertilizer to be. Once you remove the peels, you'll have a liquid fertilizer to spray at the base of your plants. Finally, to deter pests from your garden, you can slice the banana peel into tiny pieces and bury them around the plants you wish to protect.

Next time you make an omelet, hold onto those eggshells because they make a cracking fertilizer. The shells are rich in calcium carbonate, potassium, phosphorus, and magnesium, and all of these nutrients are great for your garden. Eggshells boost the alkaline levels of the soil and lower its pH levels, so it is a great choice of fertilizer for plants that thrive in less acidic soil. The smell of the eggshells can help deter deer, and their sharp edges could rid your garden of snails and slugs.

A plant's roots will benefit from the calcium carbonate found in eggshells. Strawberries, apples, lettuce, and cucumbers are just a few of the fruit-bearing plants that benefit from these natural fertilizers. However, avoid using them on beans, spinach, and cabbage. They can also cause disease in other plants that thrive in acidic conditions such as violets, azaleas, and geraniums. To prepare an eggshell fertilizer, wash and dry the shells before crushing them into a powder with a rolling pin, then sprinkle them around your plants. Along with placing eggshell pieces in your garden, you can also mix them into your flowerbed or place them in the potting mix for your indoor plants.

Who doesn't like a bit of pasta? It's versatile, goes well with a host of dishes, and is a walk in the park to cook. Next time you've finished cooking up your spaghetti, fettuccine, or macaroni, think twice before you ditch the cooking water down the drain. Provided that there's no added salt or seasoning in it, the water you cook your pasta in can be used as a low-grade fertilizer for your garden. If there's any salt, this could dehydrate your plants and lead to further complications, so make sure the water is clean. 

Pasta water is nowhere as strong or effective as a lot of the other food scrap fertilizers on this list. However, it's a great way to cut down on water use whilst adding some much-needed nutrients to your garden. Plants love starch because it gives them energy, and your leftover pasta water is full of it. The water may also contain iron and calcium, two minerals that are very beneficial for your plants. You may want to pair this fertilizer with another natural type on this list to ensure your plants are getting enough nutrients. 

The best thing about a walnut is its taste and texture. The worst is its unsightly and irksome shell. Yet, the next time you crack into one of these nutty delights, instead of throwing the damaged and unwanted shell straight into the trash, think twice and recycle it as a garden fertilizer. The shell of a walnut contains phosphorus, potassium, sodium, iron, and zinc and small amounts of manganese, calcium, magnesium, and copper. Walnut shells can make your soil more fertile, and their abrasive texture can improve the aeration of your soil. They are also great at preventing weeds and keeping moisture locked in the soil.

Walnut shells also contain amino acids, steroids, alkaloids and tannins that can help your plants fight detrimental microorganisms and repair any tissues that have been damaged. As they decompose, all this goodness will slowly be released. You can spread the shells in an even layer on your soil, but don't place them more than 2 inches deep. As they rot, the soil and the roots of the plants will absorb all the nourishing nutrients. Walnut shells are slow-release fertilizers, so it will take time to notice their effect. If you want to speed up the process, it's advised to grind the walnut shells into a powder form as opposed to letting nature do its work.

It's not just fruit peels that contain the sort of nutrients our gardens cannot get enough of, as vegetable peels are also brimming with fertilizing superpowers. Fertilizer made from vegetable peels is rich in the usual suspects of nitrogen, potassium, and phosphorous and will shower your plants with micronutrients. For the best results, gather all your potato and carrot peelings and any other vegetables you have recently sheared and place them in a container. Next, cover them with water, and let them sit for 24 hours. Pour the water through a sieve, and the resulting concoction will make a fine liquid fertilizer for your plants.

Alternatively, you can boil the vegetable peels to speed up the process. Although boiled vegetable peels are not as mineral dense, they can still be reused. If you wish to use the planting method and allow your raw or cooked vegetable peels to act as a slow-release fertilizer, dig a hole with a depth of about 8 to 12 inches and fill it with peels before covering it with soil. Remember to use small peels if you want them to decompose quickly.

If, in these austere times, you find yourself feasting on a platter of oysters instead of a bag of economy burgers, don't ditch the shells. The remnants of your seafood dish can double up as an effective garden fertilizer. Oyster shells are filled with calcium carbonate. If you don't dine on oysters all that regularly but live near a beach, even better. Take a stroll along the sands and see how many you can collect yourself. You could also try getting in touch with your nearest seafood restaurant to see if they'll save some shells from the trash can for you.

Oyster shells can help with the balance of pH levels in your soil. They also help fortify the cell walls of your plants and assist in the formation of enzymes. To use oyster shells as a garden fertilizer, you need to ensure they have been washed completely clean of salt. Once they're clean, cover the shells with a towel and smash them into tiny pieces using a hammer. It's recommended that every 100 square feet of garden should have 6 pounds of crushed oyster shell. Make sure you water the surface thoroughly after covering it with oyster shells so that the pieces don't blow away in the wind.

A world without wine would be a very dry and dismal place. It may be painful to contemplate wasting any rare vintages on your plants. However, if you have a small amount left of the bog-standard stuff remaining, why not let your garden have a little taste of the exotic grape juice? Since the 17th century, gardeners have been using the tannins in wine to combat plant diseases. Yet pouring a bottle of red directly over your garden won't just hurt your finances; it'll probably kill your plants. The trick is to take any leftover red wine (not white) and let it ferment into vinegar. By allowing the wine to spoil, you're releasing the nitrogen, which encourages plant growth.

Once the wine is no longer fit to be served with a tender piece of fillet steak, it's time to add it to your compost. Only add a small amount and don't include it too frequently, because a large amount of wine may upset the balance of the fertilizer. Once the nitrogen in the wine has activated the good bacteria, the compost is now ready to apply to your garden. Another great use for wine gone bad is as a herbicide, since it can be used to stop root growth. 

There's much more to an onion than meets the eye. The sharp-tasting and sharper-smelling vegetable has unfathomable uses, and one of them is as a fertilizer for your plants. Onion skins and peels are abundant in antioxidant and antimicrobial qualities and also contain iodine, iron, zinc, potassium, and phosphorus. The carotene in onion can help a plant stay disease-free, while the vitamin B can boost the roots and stems of your plants. Further, the vitamin PP can speed up the process whereby nitrogen becomes oxygen and encourage more growth. 

You can use dry onion skins as mulch, as the decomposing scraps will provide your soil with some much need potassium and calcium. To make an onion fertilizer, soak the leftover onion peel in 1 liter of water for 24 hours. Many dispute the merits of boiling onion scraps before using them as a fertilizer, so it's best to use lukewarm or cold water. Once you have strained the resultant liquid, you have a handy supply of onion fertilizer to add a bit of flavor to your soil. As with everything else on this list, use wisely and you'll soon notice a difference in your garden.