I grow my produce organically, and my reasoning is fairly simple. If I am going to the effort of growing my own crops, I want to make them as good and as valuable as possible. For me, that means growing them organically.
Chemical Versus Organic Fertilisers
Chemical fertilisers, also known as inorganic or synthetic fertilisers, are widely used and readily available at most gardening centres and greenhouses. They are manufactured through a process that includes refining materials to gather nutrients and often contain chemical fillers.
On the other hand, organic fertilisers are typically made from plant or animal waste or powdered minerals, such as manure, compost, bone meal, and cottonseed meal.
One of the main differences between chemical and organic fertilisers is how they deliver nutrients to plants. Chemical fertilisers provide nutrients in a readily available form, which allows for rapid plant growth.
However, they often release nutrients too quickly, leading to over-fertilisation risk and potential harm to plants and the environment. Organic fertilisers depend on soil microbes to release macronutrients such as nitrogen (N), phosphorus (P), and potassium (K) gradually over time, eventually improving soil structure too.
Another key difference is the nutrient content. Organic fertilisers contain lower nitrogen, phosphorus, and potassium levels, which means that you may need to apply a larger amount of the product to achieve similar results.
Because the nutrient ratios in organic fertilisers are difficult to guarantee, they are often sold as “soil conditioners” instead of fertilisers.
When considering chemical versus organic fertilisers, it is essential to consider their environmental impacts as well. Due to their manufacturing process and potential for over-fertilisation, chemical fertilisers can contribute to water pollution and the depletion of soil microorganisms. Alternatively, organic fertilisers can actively promote soil health and reduce the risk of environmental harm.
Here’s a brief comparison of the differences between chemical and organic fertilisers:
| Chemical Fertilisers | Organic Fertilisers | |
|---|---|---|
| Source | Synthetic materials | Plant or animal waste, powdered minerals |
| Nutrient Availability | Rapid release | Gradual release |
| Nutrient Content | High NPK levels | Lower NPK levels |
| Environmental Impact | Risk of water pollution, depletion of soil microorganisms | Benefits soil health, lower risk of environmental harm |
In the following sections of this article, I’ll introduce you to six of the best organic fertilisers for your garden and their benefits. Stay tuned for more information and tips to help you choose the best organic fertiliser for your plants and garden.
8 Top Organic Fertilisers
I’ve tried and tested numerous organic fertilisers for the best results in my garden. I’ve picked the top eight to share with you:
Animal Manure (Often Horse Manure)
One of the oldest and most effective organic fertilisers, animal manure is rich in nutrients and a great amendment to the soil. Some of the best choices include horse, cow, and sheep manure. Do ensure it is well-aged or composted to prevent the risk of burning your plants.
Compost
Creating compost from kitchen scraps, leaves, and grass clippings is a fantastic source of plant nutrients. I like to mulch my beds with compost as I follow no-dig methods. This means that I place the compost onto the beds every spring.
Overtime, the worms, rain and the plants themselves help draw the nutrients down from this fresh layer of compost.
Fish Blood and Bone
Fish blood and bone meal is a natural, slow-release fertiliser made from fishbone and fish meal. It’s high in phosphorus, nitrogen, and potassium, which promote strong root growth, healthy foliage, and better blooms. Sprinkle it around the base of your plants or mix it into the soil.
Green Manure
Green manure is a cover crop grown specifically to improve your garden’s soil. By chopping and incorporating it into the soil before it flowers, it releases nutrients and helps control erosion, suppress weeds, and increase soil fertility. Examples include clover, alfalfa, and mustard.
Worm Castings
Worm castings, also known as vermicompost, are an excellent fertiliser produced by earthworms. They’re high in nutrients and help enhance soil structure, promoting plant growth and root development. You can buy worm castings or even produce your own using a worm composter.
Chicken Manure
Chicken manure is a popular organic fertiliser option as it’s high in nitrogen, phosphorus, and potassium. Make sure to use composted chicken manure; raw manure can burn your plants.
It often comes in two forms, pellets or a more fibrous form that almost resembles compost. This is how I buy it 6x Chicken Manure.
Compost Tea
Compost tea is a liquid fertiliser made by soaking compost in water, with added microbe food and often an oxygen supply too. This helps the microbes already in the compost multiply and creates a brilliant feed for your soil.
Find out how I make my own compost tea here.
Comfrey Feed
Comfrey is a plant with nutrient-rich leaves that make a valuable organic fertiliser. Comfrey feed can be made by steeping the leaves in water, producing a liquid feed high in potassium. It’s especially good for flowering and fruiting plants, increasing yields and healthy blooms.
Environmental Benefits
The environmental impact of these natural fertilisers is significantly gentler compared to synthetic products, and there are several reasons for this.
Firstly, by using organic fertilisers, you help to improve the overall soil structure. These fertilisers contain essential nutrients that soil microbes need, such as nitrogen (N), phosphorus (P), and potassium (K). Over time, as the microbes break down these nutrients, they enrich the soil, making it healthier and more fertile.
Another reason I choose organic fertilisers is their ability to reduce the risk of nutrient runoff. Synthetic fertilisers often contain high concentrations of water-soluble nutrients, which can lead to pollution in nearby water sources if not managed properly. On the other hand, organic fertilisers release their nutrients gradually, which means there’s less likelihood of nutrient runoff affecting the surrounding environment.
Furthermore, organic fertilisers contribute to a more balanced ecosystem by supporting the growth of beneficial microorganisms. These microorganisms play a vital role in maintaining soil health, nutrient cycling, and plant growth. By opting for organic fertilisers, I also actively support sustainable farming practices that integrate the use of natural resources and minimise waste.