The Pros and Cons of Organic Fertilizers

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pros and cons organic fertilizers

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Organic gardening has surged in popularity as more people realize synthetic fertilizers’ effects on the environment. Most people choose organic fertilizers because they are made from natural elements, making them better for plants and the environment.

But are organic fertilizers really the best option? We’ll explore the pros and cons and help you decide whether they’re suitable for your garden.

Organic Fertilizers: What Are Your Options?

types of organic fertilizers

Organic fertilizers come from organic sources, such as animal manure, plant residues, and other natural substances.

These fertilizers provide nutrients to plants in a slow-release manner and improve soil health by increasing the soil’s organic matter content.

The nutrients in these fertilizers are not immediately available to plants as they are in synthetic fertilizers. Instead, the organic matter in these fertilizers must first be broken down by soil microbes before the nutrients become available for plant uptake.

This slow-release mechanism ensures that plants receive a steady supply of nutrients over an extended period, reducing the risk of over-fertilization, which can lead to environmental pollution and plant damage.

Types of Organic Fertilizers

  • Compost: Compost comprises decomposed organic matter like leaves, grass, and food scraps. It is rich in nutrients and microorganisms that can improve soil health and fertility.
  • Manure: Manure is the waste produced by livestock and is an excellent source of nutrients like nitrogen, phosphorus, and potassium.
  • Bone meal: Bone meal is made from the ground-up bones of animals and is high in phosphorus, essential for root development and flower production.
  • Blood meal: Blood meal is made from the dried blood of animals and is a good source of nitrogen necessary for plant growth.
  • Fish emulsion: Fish emulsion is made from fish waste and is a rich source of nitrogen, phosphorus, and potassium. It is commonly used as a liquid fertilizer.
  • Seaweed: Seaweed is a good source of micronutrients like iron and zinc and growth hormones that can promote plant growth and development.
  • Green manure: Refers to plants like clover or alfalfa that are grown specifically to be turned under and used as a fertilizer.
  • Worm castings: Worm castings are the waste produced by earthworms and are high in nutrients like nitrogen, phosphorus, and potassium. They can also improve soil structure and water retention.
  • Bat guano: Bat guano is the excrement of bats and is high in nitrogen, phosphorus, and potassium. It is commonly used as a soil amendment and fertilizer.
  • Rock phosphate: Rock phosphate is a naturally occurring mineral high in phosphorus. It is slow-releasing and can improve soil fertility over time.


The Pros of Natural Fertilizers

organic fertilizer

Improve soil health

Unlike synthetic fertilizers, organic fertilizers improve soil structure, promote microbial activity, and increase nutrient availability. This leads to healthier soil and improved plant growth, which results in more nutritious and flavorful produce.

These fertilizers improve soil health by increasing the organic matter content. Organic matter provides food for soil microorganisms, which in turn breaks down the organic matter into nutrients that plants can use.

This process increases the soil’s fertility and water-holding capacity, which results in healthier plants.

They enhance soil structure. By creating a crumbly soil structure, organic fertilizers allow air and water to move freely through the soil, promoting deeper root growth and minimizing soil erosion.

They also promote soil microbial activity. Soil microorganisms are essential in breaking down organic matter and releasing nutrients for plant uptake. Sustainable fertilizers provide a food source for these microorganisms, increasing their population and soil activity. This, in turn, improves soil fertility, leading to healthier plants and better-tasting produce.

Environmentally friendly

Most experts consider organic fertilizers more environmentally friendly compared to their syntheitc counterparts. They are typically derived from natural sources such as animal waste, plant matter, and compos, making them sustainable and renewable.

Secondly, they promote soil health by increasing soil biodiversity, improving soil structure, and enhancing water-holding capacity. This helps reduce erosion and nutrient leaching, which significantly contribute to water pollution.

Safe for humans and pets

Unlike synthetic fertilizers, which may contain harmful chemicals and toxins, organic fertilizers come from natural materials that are non-toxic and pose no threat to people or animals. This means you can feel confident using these fertilizers in your garden without worrying about potential health risks.

The Cons of Organic Fertilizers

garden pests

They can attract pests and wildlife.

One potential drawback of organic fertilizers is attracting pests and wildlife to your garden. They are made from natural materials, such as bone meal and fish emulsion, that attract insects and animals.

While beneficial in some cases, such as attracting pollinators to your garden, it might lead to an overpopulation of certain pests, like aphids or slugs, which can damage your plants.

It’s vital to monitor your garden regularly and take action if you notice increased pest activity, such as using organic pest control methods or adjusting your fertilizer application to avoid overfeeding your plants.


They may not provide enough nutrients

Another drawback is that these fertilizers may not provide enough nutrients to meet the needs of certain plants. The nutrient content of organic fertilizers can vary widely depending on factors such as the source material, the processing method, and the composting conditions.

Additionally, organic fertilizers may release nutrients more slowly than synthetic fertilizers, so plants may not receive the nutrients they need on time.

As a result, gardeners may need to supplement their organic fertilizer with other sources of nutrients, such as compost or synthetic fertilizers, to ensure that their plants get all the nutrients they need to thrive.


Organic fertilizers are a game-changer for your garden, health, and the environment. By making the switch, you are improving your plants’ health and vitality and contributing to a more sustainable and eco-friendly future. Give organic fertilizers a try and reap the sweet rewards of a healthier, more vibrant garden.

  • Luke Rooks

    Luke is a passionate environmental advocate based in upstate New York. When he's not sharing tips on sustainability and wellness, you can find him hiking with his dog, Max.

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