Everything You Need to Know About Organic Fertilizer

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Plants need nutrients which is why most gardeners will add fertilizer to their soil. While you can easily purchase chemical fertilizer, there are also plenty of organic options. Here are some popular organic fertilizers you can use for your garden.

Everything you need to know about organic fertilizer: Organic fertilizers come from natural sources, such as food scraps, animal dung, and minerals. These fertilizers slowly release nutrients into your garden which feed your plants and make them healthier.

What is an organic fertilizer?

Organic fertilizers are made from natural sources, be they from animals, plants, or minerals. In order for it to be classified as organic, the fertilizer needs to be found in nature and not synthetically made.

There are many sources of organic fertilizer but basically, as the substance starts to decompose, it will release nutrients into your garden that your plants need to thrive.

What are the main categories of fertilizers?

There are so many types of organic fertilizers but most can be categorized into smaller groupings.

organic plant fertilizer


By far the most common type of organic fertilizer is compost. This is a bit different than other organic compost, however, as it is made of a mixture of materials instead of a solitary one.

Most gardeners will have a compost bin and be familiar with its uses. However, if you are new to composting, it is pretty simple to get started.

First, you will need a container to store your compost in. While you can use an open box or even just mound your compost, using a black container will speed up the process as it creates a warmer environment.

Good compost is made up of a mixture of green and brown materials. Green items include fruit and vegetable scraps while brown items include leaves and other old plant materials.

Layer brown and green materials in your compost bin and add water if the mixture dries out. It’s important to turn your compost regularly to create better airflow.

As the materials break down, the compost will retain important nutrients. You can add compost to your garden as needed. The texture of compost also provides soil aeration and retains water.


If you happen to live by the seashore, be sure to collect some seaweed for your garden. It makes for excellent organic fertilizer.

You can add seaweed right into your garden. Simply cover it with some soil and as the seaweed breaks down, it will release important nutrients into your garden, such as iron and zinc.

Cottonseed Meal

While not as common as other plant-based organic fertilizers, cottonseed meal has a lot of benefits. It is most commonly bought and looks like a fine, dust-like substance.

Cottonseed meal is an amazing source of nitrogen and also includes some traces of phosphorus and potassium, so it is best used when you want a lot of foliage, such as with grass seed.

One of the major benefits is that cottonseed meals can create a better soil environment, including better aeration and water retention.

Alfalfa meal

If you want to put more effort into your garden, you can plant alfalfa as ground cover and then use the cuttings as a type of green compost. However, if you want an easier route, you can simply use an alfalfa meal.

With this substance, the alfalfa plant is ground up so it is absorbed into the soil faster. While it does not have a lot of nitrogen, phosphorus, or potassium, the results are slower but still steady.

It is best to use alfalfa meal for vegetable gardens as it will steadily release nutrients into the soil. You can also add it to your soil at the beginning of the growing season.

Grass clippings

While you can certainly add grass clippings to your compost bin and allow them to break down naturally, there is also an easier way to access their benefits.

When mowing your lawn, leave your grass catcher off. Then, the grass clippings will fall onto your yard and within a few days will decompose and add their nutrients to the soil.

Grass clippings have the added benefit of providing shade to your grass which helps retain moisture. It’s the easiest way to fertilize your yard.

organic animal fertilizer

Bone meal

As far as animal fertilizers go, bone meal is a staple for most gardeners. While it is made up of crushed animal bones, which can seem a bit queasy, it has a lot of benefits for your garden.

Bone meal is rich in calcium and phosphorus, as well as some nitrogen. It is especially useful for new seedlings and flower bulbs.

After digging a hole for new flowers and bulbs, simply sprinkle some bone meal into the area. You don’t need to worry about bone meal-burning plant roots as you would with chemical fertilizer.

Animal manure

Another staple for gardeners is animal manure. Popular choices include cow and chicken manure, as well as bird guano.

Manure not only offers nutrients for your garden but also increases the moisture density in the soil. This makes for a lighter, airier environment for plants to grow.

Fish meal

Made from fish, fish meal gives your garden a rapid burst of nutrients. It is considered a fast-release fertilizer so is best paired with other options that will slowly release their nutrients.

Fish meal is rich in calcium, nitrogen, and phosphorus. It not only improves the health of your soil but creates an environment where plants will thrive.

Blood meal

Another option with an unfortunate name, blood meal is indeed made from animal blood but comes in a dried form. It is rich in nitrogen and releases this quickly and as a bonus, its smell will repel insects.

Just be careful with blood meal as using too much of it can burn plant roots. Be sure to add water when using it to properly dilute the blood meal into the soil.

Worm castings

Having a worm compost station is an alternative to a regular compost bin and provides many, concentrated benefits. Basically, you feed the worms and as they poop, also known as castings, you can collect them and add them to your garden.

In order to get the best results, you should help the worms out by pulverizing any scraps first. Make a sort-of smoothie for your worms to help them digest it better.

organic mineral fertilizer

Rock phosphate

Made from mineral clay and rocks, phosphate helps with the composition of your soil. If you are struggling with soil that is acidic and are having trouble with the growth of young plants, rock phosphate can help.


This organic fertilizer is made from sandstone and is a great source of potassium, magnesium, and iron. While it isn’t always used in gardens, it is an important addition to fruit trees and orchards.

Greensand can help aerate the soil which allows more water to penetrate. This then allows the roots to grow stronger and reach more water sources.

How does organic fertilizer compare to inorganic fertilizer?

Type of nutrients

Both organic and inorganic fertilizer supplies important nutrients to your garden. However, with organic fertilizer, you are not guaranteed the percentage of specific nutrients.

Instead, organic fertilizer depends on decomposition from natural sources. While you may know what kinds of nutrients are in them, such as nitrogen or calcium, the exact ratio is entirely dependent on nature.

Inorganic fertilizer, on the other hand, is made through a chemical process. As a result, you know exactly how much of a certain nutrient is in the mixture.

For combination fertilizers, you will see three numbers on a package, which represent nitrogen, phosphorus, and potassium. These are the three main nutrients all gardens need.

You can also find single-nutrient types of inorganic fertilizers. For instance, if your crops need calcium, you can simply purchase this compound to add it to your garden.


Some organic fertilizers, such as compost, will have a lot of depth to their substance. This means that you may need more compost to get more nutrients into your garden.

Other organic fertilizers, such as bone meal, will be more concentrated. You will need less of this substance to impact your garden.

Inorganic fertilizer, however, has a similar concentration, no matter what type you use. In fact, most of the time these will be granules unless they have been pre-added to water.

When you use powdered inorganic fertilizer, you must use a lot of water. This is to move the fertilizer around in your garden and break it up so it doesn’t accidentally burn your plants.

Benefits of using organic fertilizer


Organic fertilizers are different than chemical fertilizers in that they work much slower to break down. As a result, nutrients are slowly released into the soil.

There is a huge benefit because it means your soil is continually getting new nutrients, which means your plants will benefit for long periods of time.

To help improve this benefit further, be sure to use different types of organic fertilizers so the release times vary. Furthermore, you will need to add more organic fertilizer to your soil every year to continue the benefit.

Fewer applications

If you plan your garden out correctly, you only have to add organic fertilizers to the area once or twice a year. This is because, as we previously discussed, organic fertilizers work slowly.

Most gardeners will add organic fertilizer to their soil at the beginning of the growing season, in the spring. Then, when you are tidying up your garden in the fall, this is another good time to add more.

Soil composition

Inorganic or chemical fertilizers are usually in the form of granules that seep into the soil with water. They do not have any form to them.

In contrast, organic fertilizers will have some depth or form to them. A benefit of this is that organic fertilizers help to make the soil less dense.

Many organic fertilizers will help store water and then slowly release it into the soil, which is very beneficial in hot summer conditions.

The soil will also be less impacted thanks to organic fertilizers, which will allow the plants to grow more easily.

How to make organic fertilizer at home

There are some fertilizers that you can indeed make at home but others are best left to the professionals. For example, blood and bone meal are not the easiest to make and the process can be pretty gruesome.

It’s best to stick to homemade plant fertilizers if you want to go this route. These are easier to create.

Compost is pretty basic and most experienced gardeners will have a compost bin in their yard. To make compost, simply add different layers of vegetable scraps and fallen leaves.

In a month or two, this organic matter will break down and you can add it to your garden.

You can also collect seaweed and add it to your garden. However, to do so, you will need to live near the ocean.

Finally, if you live on a farm, you can go about making manure compost. To do so, collect droppings from animals such as cows and chickens. Mix them with dirt and spread them around in your garden.  

Which is the best organic fertilizer?

Compost is one of the best organic fertilizers because it is so well-rounded. Because you are adding a mixture of brown and green matter, your compost will have a nice variety of nutrients including nitrogen, phosphorous, and potassium.

However, the best organic fertilizer will be one that meets the needs of your garden. If you are struggling to produce large crops, take a look at what your soil is lacking and work to amend it.

For example, bone meal is excellent when starting new plants and manure is great if you want to add aeration to your soil.


There are many types of organic fertilizers but they all come from natural sources. If you want to keep your garden healthy and natural, it’s best to use a combination of different organic fertilizers.

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