17 Organic Natural Fertilizers | DIY Fertilizer Recipes

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If you garden organically and dream of becoming self sufficient then you’re likely to want to use organic natural fertilizers to add nutrients to the soil.

Why soil needs natural fertilizers…

When we grow fruits and vegetables in soil they strip its nutrients. By adding natural fertilizer we keep the soil healthy and ensure that future crops get what they need.

The type of fertilizer you need to use will depend on your soil and the plants that you want to grow.

Plants need potassium, phosphorus and nitrogen which can all be added to your garden without the use of harsh chemical fertilizers.

What’s the problem with chemical fertilizers?

Synthetically produced chemical fertilizers have a detrimental effect on the soil and on the wider environment.

They add no organic matter to the soil and do nothing to improve the soil structure.

Unfortunately, if the chemical run off from fertilizing reaches a water source then it will reduce the amount of oxygen in the body of water killing anything that lives there.

Producing chemical fertilizers is also hugely energy intensive. Its production contributes to air pollution, global warming, and carbon footprint.

Some commercial organic natural fertilizers, (like rock phosphate) also have to be manufactured and can be expensive.

Thankfully, it’s easy for home gardeners to make their own natural fertilizers or to source locally made fertilizers.

The 17 best natural fertilizers

Organic Natural Fertilizer Recipes

Natural fertilizers can be made easily using ingredients you probably have at home.

Some amazing natural fertilizers can even be made from things that were destined for the compost heap.

1. Organic Banana Peel Fertilizer

Great for: roses and other flowering plants, house plants fruit trees, tomatoes, peppers.

Bananas are 42% potassium! They also contain calcium and phosphorous.

Bananas don’t contain nitrogen which makes it a great natural fertilizer for tomatoes and peppers.


Pop some banana skins in a jar and top with water. Allow to soak for a few days before using.

Banana peel natural fertilizer
Banana peel tea brewing alongside eggshells…ready to fertilize the garden!

How to use banana peel as a fertilizer:

Use to water around plants.

The skins can also be buried around the base of plants.

2. Coffee Grounds Natural Fertilizer

Great for: roses, magnolias, hydrangeas, blueberries and vegetables.

If you’re a coffee drinker then you have what you need to make some lovely nitrogen rich natural fertilizer.

If you don’t have your own supply of coffee grounds then you can ask at local cafes who often give it away.

Coffee is a great natural fertilizer as it helps to increase the acidity in the soil which some acid-loving plants will benefit from.

How to use Coffee as a fertilizer: Scatter the coffee grounds on top of the soil and gently combine

3. Comfrey Natural Fertilizer

Great for: use on plants that crave magnesium, like tomatoes, peppers, and rose bushes.

Comfrey has very deep roots, which means it extracts large quantities of nutrients from far below the soil’s surface, inaccessible to other plants. These nutrients are stored in its leaves.

Gardeners World

Comfrey is rich in potassium so is the perfect fertilizer for flowers and fruits like tomatoes.

Wear gloves to pull off lower leaves. Remove stems and flowers. Tear up the leaves and put them in a bucket with a brick on top to hold them down. Cover with water and put a lid on top. Leave to soak for a few weeks.

Check your fertilizer every few weeks and collect any liquid in a bottle. You can add more leaves to continue the process. Store in a cool dark place.

Planting Comfrey natural fertilizer
Comfrey is a great natural fertilizer and compost activator.

How to use Comfrey Fertilizer:

Dilute your comfrey fertilizer at a rate of about one part comfrey to ten parts water.

4. Natural Seaweed Fertilizer

Great for: Mulching soil and feeding acid and iron hungry plants like gardenias, camellias, azaleas and rhododendrons.

Seaweed has been used as a mulch and a natural fertilizer for centuries. It contains mannitol which helps plants to absorb the soils existing nutrients efficiently.

It is high in carbohydrates which are the building blocks of plants growing.


Collect the seaweed remembering that each patch of seaweed provides food and shelter for many species of marine life. Don’t collect it all from the same spot.

Add 8 cups of your chopped fresh seaweed to a five gallon bucket and fill halfway with water from your waterbutt.

Leave to soak for three or more weeks and then strain.

How to use natural seaweed fertilizer:

When you’re ready to use just mix half seaweed tea fertilizer and half water in a watering can.

5. Molasses Natural Fertilizer

Great for: all well established plants.

Molasses is more commonly used as a sweetener in baked goods but you can also use it to make a natural fertilizer for your plants.

Blackstrap molasses is high in calcium, magnesium, iron and potassium. It also contains sulfur and a host of micronutrients. Using molasses as fertilizer provides plants with a quick source of energy and encourages the growth of beneficial microorganisms.
Gardening Know How

Recipe: mix 3 tablespoons of organic molasses with a gallon of water.

How to use Organic Tea Fertilizer:

Add the molasses tea to your plants every couple of weeks.

You can also add molasses to your other natural liquid fertilizers (1-3 tablespoons per gallon). 

6. Grass Clippings Fertilizer

Great for: all established plants.

I often use the grass the mower collects to mulch around my plants but it also makes a nice natural fertilizer.

Grass clippings are incredibly rich in nitrogen and potassium. A 3-year Swedish study even showed that using grass clippings as a mulch actually improved crops and reduced  pest damage.

natural fertilizers grass clippings
Grass clippings around peas.


Place fresh grass clippings in a five gallon bucket and cover it with water.

Allow it to sit for about five days.

How to use grass clippings fertilizer 

Dilute your fertilizer 1 part grass clippings tea to 10 cups of fresh water and pour on soil.

7. Fish Tank Water Fertilizer

Great for: plants you won’t be eating soon!

Dirty fish tank water isn’t great for fish but it’s actually really good for plants.


If the water is very dirty then dilute with water before using. 

How to use Fish Tank Water Fertilizer:

Use to water plants.  Don’t use on vegetables or fruit as you’ll be eating them.

8. Homemade Fish Manure Fertilizer

Great for: plants you won’t be eating anytime soon!

Organic gardeners around the world use Fish Fertilizer as an alternative to chemical fertilizers.

Bacteria is necessary for healthy soil and a good homemade fish emulsion  will contain lots of lovely bacterial microorganisms.

Just be prepared for the smell!


Fill a bucket about 2/3 full with fish (whole or scraps) and brown organic matter (like leaf litter or sawdust) in equal parts.

Cover contents with water and put a lid over the top. Store out of the sun for a few weeks, stirring the mixture every few days.

You can also add molasses and seaweed if you want even more  nutrients in the emulsion.

How to use fish emulsion fertilizer:

Pour off the water and catch it in another bucket…this is your fish emulsion.

Dilute your emulsion before using. Mic one cup of emulsion with a gallon of water and pour on the soil or spray on leaves.

9. Egg Shell Natural Fertilizer

Great for:  Tomatoes, peppers and potted plants.

Although it’s nitrogen, phosphorus, and potassium that are most vital for healthy plant growth, calcium which is found in eggshells will help plants at a cellular level.

I also find that slugs hate crushed egg shells.


Crush clean egg shells.

How to use Egg Shell Fertilizer:

Crush and sprinkle around plants.

10. Wood Ash Fertilizer

Great for: Artichokes, tomatillos, greens and brassicas.

If you have a stove at home and burn only wood then it is a great addition to your compost heap.

You can also use it to make a natural fertilizer that’s rich in calcium carbonate and potassium.

Wood ash will raise the pH of your soil so test your soil first to make sure that it doesn’t become too alkaline.

Do not use wood ash fertilizer on acid loving plants like berries (raspberries, strawberries and blueberries), rhododendrons, fruit trees, azaleas, potatoes and parsley.

How to use Wood Ash Fertilizer:

Before planting out add the ash to your soil and gently combine.

11. Manure As A Natural Fertilizer

Great for: heavy cropping vegetables like courgettes, squashes and fruit bushes and plants like strawberries, blackcurrants.

Manure is often something that gardeners can get for free or cheap from a local farm or stables.


Choose well-rotted manure. I always ask whether organic straw or sawdust was used in the bedding as I don’t want any residual weed killer on my garden.

How to use Manure as a Fertilizer:

Take a shovel full of well rotted manure and place in the hole you’ve dug for your squash, courgette, fruit bush etc. Mix some soil and compost on top and plant.

12. Manure Tea Fertilizer

Great for: heavy cropping vegetables like courgettes, squashes and fruit bushes and plants like strawberries, blackcurrants.

You can also use manure to make a liquid fertilizer for your plants.


Put a shovel full of well rotted manure in a cotton bag or pillow case ans soak in a 5 gallon bucket for 2 weeks.

How to use Manure Tea as a Fertilizer:

Make a mix of half manure tea half water and use it to water your plants.

13. Vinegar Fertilizer

Great for: use on acid-loving plants like blueberry bushes, gardenias and azaleas.

Vinegar contains acetic acid which some plants will benefit from.


Combine a tablespoon of white vinegar with a gallon of water.

How to use Vinegar Fertilizer:

Use the solution to water your acid loving plants about once every three months.

14. Weed Fertilizer

Great for: any established plants. 

Rather than battling with weeds we prefer to leave them in certain areas for the bees and other insects.

They also make a great natural fertilizers and some are even great in salads and casseroles.

Nettles, comfrey, yellow dock and chickweed are all good to make a weed fertilizer.

How to use weeds as a natural fertilizer:

If the weeds haven’t gone to flower then cut them down and dry them in the sun before chopping them up to use as a mulch.

Throwing borage and comfrey on the compost heap will also speed the process up.

15. Worm Castings Tea

Great for: all plants.
It’s easy to make your own worm tea.

You’ll need compost worms (not earth worms) a worm composter like this and some kitchen scraps and cardboard.


Take the worm castings from your composter  (the digested soil the worms worms leave behind) and place some in an old cotton bag, pillowcase or stocking.

Place in a bucket of water and leave to soak overnight.

How to use worm casting tea:

Dilute 1 part water with one part worm tea and water your plants with it.

16. Organic Tea Fertilizer

Great for: all established plants.

This natural fertilizer has been used for centuries and is really simple to make.


In a 5 gallon (23 litres) bucket add some grass clippings or compost scraps to the top and cover with water.

Allow to sit for three days before straining.

How to use Organic Tea Fertilizer:

Use in a watering can to water plants.

17. Epsom Salt Fertilizer

Great for: use on plants that crave magnesium, like tomatoes, peppers, and rose bushes.

Epsom salts are great for relieving aching muscles after a busy day in the garden but they also work well as a natural fertilizer which is rich in magnesium.

Simply mix 1 tablespoon of Epsom salt per gallon of water.

How to use Epsom Salt Fertilizer:

Use a watering can to apply to indoor and outdoor plants.

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organic natural fertilizers recipes pin

organic natural fertilizers recipes pin

So, there you are…17 organic natural fertilizers to try. What’s your favourite oraganic fertilizer?

4 Comments on “17 Organic Natural Fertilizers | DIY Fertilizer Recipes

  1. Brilliant post, thank you! I already knew some of these but the rest are new to me. So pleased I have found even more ways to source organic fertiliser with no extra consumption/purchases required!!

  2. Great job! don’t forget weeds like burdock which have great deep roots, and nettle – which also makes a great anti-inflammatory tea for us gardeners.
    Thank you for the Epson salts tip, I’d forgotten about that one. Carry on!

  3. The best article. It teaches me to save money without sacrificing the health quality of the fruits and vegetables that soon I will reap. Keep sharing more DIY fertilizer recipes.

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