The Best Food Scrap Fertilisers for Plants

Did you know that plants can eat the same foods as humans? As weird as it may sound, if you have a healthy diet, you can use some of your food scraps as fertiliser for your green companions. If you’re into organic gardening, want to reduce food waste, and save money, this article is for you! Over the following paragraphs, we’ll let you in on a few secrets about the best household snacks that you can recycle and repurpose successfully in your garden.

If you’re an experienced gardener, you might already know that plants need many different types of micronutrients to thrive, but in general, there are three key nutrients that you’ll find in most store-bought fertilisers: nitrogen, phosphorus, and potassium. If you’ve ever seen the term NPK on the label, that’s what it was referring to. The great news is that these nutrients can also be found in some of your favourite snacks. So, why spend time and money on store-bought plant food, when you might have everything you need in your pantry?

The ratio of carbon to nitrogen required to make awesome compost is about 30:1. You need a lot of carbon to get the composting process happening properly without becoming anaerobic. Torn newsletters or shredded paper from the office or dried grass clippings or fallen leaves for example. Add a big quantity of these to your food scraps and not only will people be reducing their food waste but also creating new healthy soils at the same time!

Keep reading to find out why it’s important to use food scraps as fertiliser. What food scraps make the best plant food, and how to reduce food waste through gardening. 

Why Is Using Food Scraps as Fertilisers Important?

There is a common myth that gardening is expensive. If you’re familiar with this idea and you are afraid that focusing on your garden isn’t something that you can afford right now, you’ll be happy to learn that gardening doesn’t need to have a negative impact on your budget. 

While it is true that in the past beautiful gardens were associated with wealth, things have changed quite a bit. So, unless you plan on buying the most expensive tools or the most exotic plants, there are many gardening tricks that can help you save money and turn your garden into a resource. A very simple activity such as turning food scraps into homemade fertiliser can actually save you money.

For starters, you can grow your own food without using mass-produced, store-bought synthetic fertilisers that, according to Heirloom Soil, are very harmful. By using natural fertiliser, you can be sure that the fruits, veggies, and herbs that you’re growing are organic and not contaminated with any unhealthy substances. 

Chemicals in your Fertiliser

Using food scraps as fertilisers can make a huge difference in cutting gardens, vegetable gardens, and herb gardens. Food scraps might be beneficial as fertilisers for indoor plants as well. A nutrient-rich compost will encourage growth and your garden will become more productive and bountiful. Begonias, banksias, zinnias and most garden plants will produce beautiful blooms if you enrich their soil with organic compost.

Furthermore, if you avoid using chemicals in your garden, you also lend a helping hand to the local flora and fauna. Organic gardens can become a healthy ecosystem populated by native bees and other essential pollinators. In fact, attracting native bees is really good for your plants, so you might want to consider installing a bee hotel as well.

Now, before you start reading the list below, it’s important to mention that in order to use food scraps in your garden, you need to build a compost heap. There are many things that you’d normally discard that can be composted, including foods. To achieve the best results, your fertiliser heap needs to contain two types of materials: green (high in nitrogen, such as food scraps) and brown (high in carbon, such as dried leaves). Variety is key when it comes to compost, and more ingredients equal a better final product that is rich in micro-nutrients and beneficial microorganisms. To accelerate the composting process, gardeners can also use certain worms that have the ability to break down organic matter at a fast pace. 

That being said, let’s take a look at the following foods that you can use to feed your plants.

Food Scrap #1 – Banana Peel

If you’re new to the whole scrap food compost thing, you might be wondering what are some great examples of food scraps that you can throw in the compost pile. Banana peels are a great example as they add nutrients and organic material to your fertiliser mix. Bananas being high in potassium promotes flowering and fruiting. They will also add sodium, potassium, phosphates, magnesium, calcium, and sulfur which will benefit your plants and encourage blooming and fruiting.

A great thing about bananas and other fruits and veggies, in general, is that they tend to decompose rather quickly. This is great, especially if you want to rush the composting process. If you are wondering how to turn banana peels into plant fertiliser you’ll be happy to learn that it’s really easy. All you have to do it to toss the leftover banana parts into the compost pile. Cutting them into smaller pieces will speed up the process even more, but throwing them in whole isn’t an issue either.

A very common question that always pops up when it comes to feeding plants with food scraps is whether or not bananas or other scraps can be added directly to the soil. You’ll find many different opinions out there, but if you ask us, we recommend composting the food scraps before adding them to the soil, and banana peels make no exception. So, if you happen to stumble across articles that encourage you to put banana peels under the roots of roses before you plant them, to bury them under your other plants, or to make banana peel tea, take the info with a grain of salt and do some extra research, as buried food scraps might not benefit your garden and teas can attract pests.

Food Scrap #2 – Bread

There is quite some debate on whether or not stale bread should be composted. Bread, be it stale or fresh, is an organic product that decomposes easily. Interestingly enough, a lot of people warn against adding it to the compost bin and, thus, a lot of gardeners feel that it’s better to simply throw it away. But why is that? As it turns out, the main worry that people have when it comes to composting bread is the possibility of attracting rodents. We think that this issue can easily be avoided by simply mixing the bread with the rest of the compost and by keeping the compost bin closed, which is something that you would probably do anyway. If, however, your compost pile is exposed, you can simply hide the tasty bread scraps under the rest of the pile. 

So, if you want to avoid wasting food and wish to put your stale bread to good use, there’s you can add it to your compost without worries. Soaking bread in a bucket of water and then pouring it in – is basically disintegrates that way and breaks down super fast. Bread will break down quickly and it will boost the nitrogen levels of your compost pile. As soon as it is exposed to moisture, bread falls apart almost instantly, especially if you cut it into small pieces and if it is already a bit mouldy already, even better.

Food Scrap #3 – Wine and Grapes

Compost item-3: Grapes
Image by Jill Wellington from Pixabay

If you are lucky enough to have a lot of wine and grapes and are not sure what to do with them once they go bad, we have good news. Wine and grapes are great for compost and you can throw them in your composting bin without worries. The best thing about them is that they decompose really quickly, which is something you can easily notice if you keep them in a fruit bowl for too long.

Everything related to grapes can make great compost and add a lot of nutrients to your fertiliser. So, if you make homemade wine, you can compost the leftover grape skin and seeds. These leftovers, also known as pomace, consist of approximately 57% pulp, 25% skins, 10% stems, and 8% seeds which are all rich in potassium, calcium, nitrogen, and phosphates. 

You can fertilize your plants with leftover wine and even beer which has a lot of yeast and can activate the compost. A great advantage of composting these nutritious liquids is that they can help keep your compost moist and keep the good bacteria alive. An important thing to remember about alcoholic beverages is that they need to be used in moderation, as too much alcohol in your compost might kill the beneficial microorganisms, and without them, your compost won’t decompose effectively. You can offset the acidity of grapes with alkaline ingredients such as a handful of garden lime or even just balancing with paper and cardboard – use the cardboard wet if you system is dry, or use it dry if your system is too wet.

If you add grapes to your compost, don’t forget to turn it regularly to ensure that all the elements mix well. If you’re worried about pesticides and want to prevent contaminating your soil, you can soak the grapes in vinegar and rinse them with clean water before using them. Keep an eye out for pests, as woody stems and prunings can sometimes show traces of infestation. If you notice anything suspicious, avoid using them as compost.

Food Scrap #4 – Tea

Compost item-4: Tea Leaves
Image by lloorraa from Pixabay

Tea leaves make perfect plant food and you can definitely add them to your compost heap. Fresh tea leaves as well as used tea scraps are rich in nutrients and tannic acid. These substances will make your soil more fertile. In essence, tea is natural, organic matter, that will decompose quickly, boosting the activity of beneficial bacteria and earthworms. 

It is important to mention that adding tea leaves directly to the soil, might not benefit all plants. The aforementioned tannic acid can be a nice addition for plants that thrive in acid soils, such as ferns and roses, but they might be harmful to plants that need alkaline soils. The safest way to feed your plants is by composting your tea scraps instead of adding them to the soil directly. If your roses are not in bloom yet and you need to offer a nice bouquet, you can always opt for a long-term buddy such as a happy plant or a spider plant.

Be extra careful when it comes to tea bags. We don’t recommend adding tea bags to your compost because studies have shown that they can contain plastic. As you already know, plastic will not decompose in your compost heap, and these plastic particles will be transferred to your garden. So, to be on the safe side, you can remove the leaves from the bag before composting them, you can avoid using tea bags altogether and switch to leaf tea, or you can read the label carefully and make sure that the bags are biodegradable. Either way, your leftover tea leaves will make great plant food. 

Wondering if coffee grounds work the same? Keep reading our article to find out!

Food Scrap #5 – Corn Cobs and Husks

Compost item-5: Corns
Image by Cornell Frühauf from Pixabay

Corn is delicious and it’s a key ingredient in many of our favourite snacks. Whether you prefer to eat grilled corn at a Sunday barbecue, oven-roasted for dinner, steamed or boiled, you might be left with a garbage bin filled with husks and cobs. But, instead of throwing them away, you can use them to make nutritious compost for your plants. Gardeners love to add corn leftovers to their compost bin as they add aeration. This means that the compost will be enriched with bacteria, worms, mould, and algae that have an essential role in transforming these leftovers into plant food.

However, there is one thing that you need to be careful about when composting corn cob stalks – it needs some preparation beforehand. Being quite large and fibrous, cobbs might take a lot of time to decompose. They provide habitat for worms to move in and you will find in time they are like a baby worm nursery! When harvesting compost, I just throw the big stuff back in for another round, though there is no harm in corn cobs ending up in your soil in the veggie patch anyway! Same goes for avocado pips and mango pips. While it’s true that this process might be a bit tedious, it will be worth it in the end, as the small pieces of corn will create air pockets and accelerate the composting process, instead of slowing it down.

Corn cobs tend to decompose very slowly. Therefore it’s best to avoid combining them with other materials that break down slowly. For best results, mix them with wet food scraps such as lettuce leaves, potatoes, and tomatoes. Needless to say, any corn products such as corn flakes and nachos can also be composted.

Food Scrap #6 – Eggshells

Compost item-6: Eggshells
Image by congerdesign from Pixabay

Adding eggshells to your compost is a great way to reduce food waste. They are also a rich source of nutrients and calcium. More specifically, chicken eggs contain calcium 34%, organic matter 5%, magnesium 0.3%, sodium 0.05%, phosphorus 0.04% and potassium 0.03%.

According to this article published on the Michigan State University website, you can add eggshells to your compost pile. As long as they come from properly cooked eggs. Why? Because chickens might transfer salmonella to their eggs and high temperatures kill this bacteria.

It is important to mention that eggshells have a very slow decomposing process. Therefore they might still be visible once your compost is finished. Although this won’t do any harm to your plants, it might affect the overall aspect of your garden. If you want the eggshells to break down faster, before you add them to your compost bin. Perhaps take some time to dry them in a warm oven and crush them.

So, adding eggshells to your compost is beneficial. However, eggshells get their fair share of controversy online. If you’ve been searching for something along the lines of ‘how to use eggshells in the garden’, you’ve probably come across hundreds of articles that encourage readers to use eggshells to prevent blossom end rot, as a slug repellent, as mulch, or as organic pesticides. This article does a great job at debunking some of these myths. So we should just stick to adding them to the compost bin for now.

Food Scrap #7 – Coffee Grounds

Compost item-7: Coffee Grounds
Image by Couleur from Pixabay

According to Statista, the national coffee consumption rate is around 1.96 million sixty-kilogram bags. Additionally, each Australian consumes on average 1.91 kilograms of coffee per year. Chances are you are also enjoying this flavourful product and are looking for ways to repurpose the scraps. However, adding coffee grounds to your compost or to your garden soil is a very controversial practice. There are hundreds of websites encouraging coffee lovers to put their leftover coffee grounds to good use in their garden. There are also others that warn against it.

Many internet gardening gurus and influencers support the idea that throwing your used coffee grounds into your compost pile. This is because it adds some of that much-needed nitrogen that will help your plants thrive. Some gardeners even opt for adding their used coffee grounds directly to the soil. However, it is important to point out that doing this might have a negative impact on your plants. This is based on this Rural Sprout article.

It is commonly believed that fertilising your garden with coffee grounds has many benefits such as improving soil drainage. As well as reducing water retention, making the soil more aerated. Which attracts beneficial microorganisms and earthworms, but this study shows the opposite of that. So, coffee grounds had to be on this list because we felt it was important to share this interesting info. Now you can decide whether or not using coffee grounds in your garden is worth the risk.


What is food fertiliser?

Food fertiliser is recycled and composted food waste that is used to improve the soil and to feed the plants. If you want to feed your plants with organic fertiliser while also recycling. Repurposing your food scraps and composting your leftovers make food fertiliser is a great option. Keep in mind that, according to gardening experts, it’s highly recommended to compost the food. Rather than to add it directly into the soil. By composting the food, you ensure that it goes through the natural process of decomposition. Before it reaches your plant’s roots. This way, you avoid problems such as attracting pests, root damage, slow decomposing process, etc.

What other food can be used as fertiliser?

Looking for some other foods that you can use as plant fertiliser:

  • Fruits and veggies (in any form: cooked or raw, scraps and peels, and even mouldy or rotten).
  • Vegetarian cooked foods (rice, grains, pasta, sauce, eggs, casseroles, beans, soups, etc)
  • Herbs and spices
  • Dairy products in small quantities
  • Soy/rice/almond/oat/coconut milk
  • Stale bread, tortilla, pita, nachos
  • Tofu and tempeh
  • Pumpkin, sunflower, sesame seeds (crushed, to avoid sprouting)
  • Energy and protein bars
  • Jelly, jam, and preserves
  • Beer and wine

As you can see, you can compost pretty much all types of vegetarian food scraps.

Potatoes peeled in a bowl with skins beside to compost as fertiliser
Image by Christos Giakkas from Pixabay

What food should never be used as fertiliser?

You should always avoid adding meat and dairy products to your compost heap. Although they are perfectly biodegradable, they tend to attract pests. You can add a few spoons of ice cream or some yoghurt without having any issues. As long as you mix them into the pile and do not leave them exposed.

Oily and greasy food should also be avoided as they might affect the decomposing process of your compost. Oils tend to prevent decomposition, and you don’t want that.

Too many acidic foods such as pickles, citrus fruits, and tomatoes can harm the beneficial microorganisms that break down your compost. You can certainly add a few tomatoes or oranges, but keep the mix balanced.

While beer and wine are on the green list, too much alcohol can kill the beneficial bacteria. Therefore add in moderation.

Some gardening experts also advise against composting bread and baked goods for similar reasons. But these products decompose really quickly, so they are not as problematic. Especially if you hide them at the bottom of your compost.


Food waste is a real issue. We can easily avoid being a part of it by recycling and repurposing as much as we can. One man’s trash is another plant’s treasure, as the saying goes. Composting all your vegetarian food scraps comes with a lot of benefits such as saving money. As well as feeding your plants, keeping your garden eco-friendly, and making your garden pollinator-friendly. So, if you want to transform your scraps into fresh products, you should definitely start composting.

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