Organic vs. Mineral Fertilizer: The Differences Explained

If you want to give your lawn or plants some extra strength and resilience, you’re likely considering using fertilizer. The two types of fertilizers you can choose between are organic and mineral, and it’s essential to learn about each before deciding which is best for you. So, what is the difference between organic and mineral fertilizers?

Organic fertilizer consists of organic matter–like animal manure–and doesn’t contain synthetic chemicals or minerals. Mineral fertilizer contains the same nutrients as organic fertilizer but in higher concentrations. It also includes synthetic materials, unlike organic fertilizer.

In this article, I’ll be walking you through the primary differences between organic and mineral fertilizers in greater detail. I will also discuss the pros and cons of each option, if one is better than the other, and if both are safe for all plants.

Are Organic and Mineral Fertilizers the Same?

Organic and mineral fertilizers are not the same. While they both contain the three primary macronutrients (nitrogen, phosphorus, and potassium), organic fertilizer is free from synthetic materials. As a result, organic and mineral fertilizers are made differently and can vary in strength.

To better understand how organic and inorganic fertilizers differ, it’s helpful to consider the pros and cons of each. 

Organic Fertilizer Pros

There are many pros to using organic fertilizer. One significant advantage is that you can make it at home, unlike mineral fertilizer. For example, you can make a compost pile at home using grass clippings, fruit and veg waste, or twigs. 

To learn more about the primary pros of organic fertilizer, read below.

You Can Make It at Home

As mentioned, one pro of using organic fertilizer is that you can make it at home. While buying the stuff might be easier, it’s also more expensive. And since mineral fertilizer is made of chemicals, it’s impossible to make it at home (unless you have all the materials and equipment, which is highly unlikely!).

Here are some examples of organic fertilizers you can make at home:

You can save some money if you already have all the materials you need to make organic fertilizer.

There Are Different Options

Regarding organic fertilizer, there are different options to choose from. There isn’t just one particular organic fertilizer. Blood meal, bone meal, and compost are all examples of materials you can use as organic fertilizers.

So, let’s say you want to make fertilizer at home but don’t have any livestock (meaning you can’t use manure as fertilizer). Instead, you might have grass clippings, twigs, and food leftovers. In that case, you could create a compost pile and use that as organic fertilizer.

It’s Usually Slow-Release

Many organic fertilizers release nutrients slowly, meaning they last a long time–this is a massive benefit because you don’t have to reapply it to the soil as often as you need to apply many mineral fertilizers.

If using organic compost as fertilizer, you’ll only need to re-apply it once every 1-2 years. On the other hand, you’d need to re-apply mineral fertilizers at least twice a year.

It Improves the Soil’s Quality

Not only does organic fertilizer feed the soil and surrounding plants, but it also improves the overall quality of the soil. Many people use compost to fertilize and amend their soil because it contains vital nutrients and improves drainage and structure. 

Organic fertilizer can improve the quality of any soil–if you have dense, clay soil, organic compost fertilizer will promote drainage and help loosen the consistency. If you have sandy soil, organic compost fertilizer will encourage water retention and help it become more firm.

So no matter what type of soil you’re dealing with, organic fertilizer (mainly compost) will improve its quality.

Organic Fertilizer Cons

Now that you know the primary pros of organic fertilizer, you probably want to learn more about the cons. Unfortunately, there are a few cons to consider before using organic fertilizer. However, it’s up to you to decide if the pros outweigh the cons.  

Below are the leading organic fertilizer disadvantages you should consider.

Not Highly Concentrated

While organic fertilizer does contain the essential nutrients that all plants need, it doesn’t contain them in high amounts. 

Using organic fertilizer shouldn’t be a problem if you want your soil to receive a lower concentration of essential nutrients. However, if you’re looking for something specific (for example, a fertilizer high in phosphorus but low in other nutrients), it’s better to use mineral fertilizer.

Alternatively, if your soil is severely lacking in all nutrients, organic fertilizer may not be enough to fix the issue. And since most organic fertilizers contain a low NPK ratio, it’s easy to over apply it accidentally.

Although organic fertilizer is less concentrated, it generally contains a wider array of micronutrients.

You Can’t Control the Strength As Easily

If you decide to make organic fertilizer at home, you’ll realize that it’s not easy to control the strength (i.e., the level of nutrients). With homemade organic fertilizer (like compost), you have to guess the precise amount of each nutrient present in the fertilizer. 

Let’s say you decide to make a compost pile as organic fertilizer. You would add grass, wood, and some food leftovers to do this. But as you’re adding these “ingredients”, you won’t know precisely how much nitrogen, potassium, and phosphorus you’re equipping the fertilizer with.

When it comes to mineral fertilizers, the strength of each nutrient is displayed on the packaging (in the form of N-P-K). This is also sometimes displayed on some organic fertilizers, but not all.

It Takes Time To Work

You can’t make organic fertilizer in five minutes and expect it to work that day. Instead, you need to gather the materials and prepare them. You also need to wait (usually a few weeks) so that it can begin decomposing. 

Organic fertilizer won’t be able to feed the soil until it begins decomposing, so if you’re looking for something that works fast, you’ll want to consider a mineral fertilizer.

Expensive

Organic fertilizers are expensive, which is a big turn-off for many people. It’s particularly annoying for people who own small farms and don’t have much money to spare. Plus, it’s often not worth it for small farmers to purchase bags of organic fertilizer if it removes the chance of any profits. 

However, many organic fertilizers are long-lasting and only need to be applied once or twice a year, so the price is sometimes worth it. Moreover, using organic fertilizer can help improve your soil’s structure by acting as a soil amendment, which is another reason why the price is sometimes worth it.

Mineral Fertilizer Pros

You now know more about the pros and cons of organic fertilizer. Next, you should learn about the pros of mineral fertilizers. Mineral fertilizers are convenient, and you can use them instantly, which is why many people gravitate toward them. 

Below, I’ll discuss the main pros of mineral fertilizers.

Highly Concentrated

Mineral fertilizer is more concentrated than its organic counterpart. Therefore, it’s better to use it if your plants and soil are in desperate need of nutrients. Most organic fertilizers contain lower amounts of nutrients, so while they’re still beneficial, they’re not always enough to work effectively.

You Can Choose Different Strengths

Although you can find highly concentrated and robust mineral fertilizers, you can also find weaker ones.

For example, you can buy a mineral fertilizer with very high levels of nitrogen, and lower levels of the other macronutrients–this type of fertilizer might be helpful for plants like trees or grass. Many mineral lawn fertilizers have this type of concentration.

On the other hand, you can’t find an organic fertilizer with that concentration. So, anytime you need a specific level of nutrients (particularly a high concentration), it’s best to go with mineral fertilizer.

You can also buy mineral fertilizers for different plants. For example, some mineral fertilizers are made for evergreen trees and shrubs. Others are made specifically for fruit trees. So while organic fertilizer is often a general plant and lawn feed, mineral fertilizer comes in various strengths suitable for specific plants.

There Are Slow and Fast Release Options

Most organic fertilizer is slow-release with no way to make it release nutrients faster. However, mineral fertilizers can be slow and fast-release. For example, liquid mineral fertilizers work much quicker than granular mineral fertilizers. So whether you’re looking for fast or slower results, mineral fertilizers will have you covered.

No Preparation Needed

A common type of mineral fertilizer is granular, and this particular fertilizer doesn’t need any preparation. You can apply it directly to the soil without the need to prepare or mix any ingredients–this is extremely convenient if you don’t want to spend much time on fertilization.

Fertilizer spikes work the same way–they can be applied directly to the soil from the packaging, no preparation needed. On the other hand, you need to prepare organic fertilizer if you make it at home. And once it’s prepared, it takes weeks for it to decompose.

More Inexpensive

Most mineral fertilizers are more inexpensive than organic ones, making them an attractive option for people who want to save money. Although you can make organic fertilizer at home cheaply, the store-bought varieties are anything but it. 

And just because mineral fertilizer is less expensive doesn’t mean it’s worse. In many cases, it can even yield better results.

Mineral Fertilizer Cons

Although there are many pros of using a mineral fertilizer, there are also cons to consider. The main con of mineral fertilizer is that it is easy to misuse accidentally, which can severely harm your plants and lawn. Therefore, it’s vital that you always read the instructions carefully and avoid using too much product at once.

Below are the main cons of a mineral fertilizer.

It Can Burn Soil/Plants

Unfortunately, it’s common for mineral fertilizer to burn soil and plants. This occurs when you use the incorrect type of mineral fertilizer or if you overuse it. For example, if your soil already contains high nitrogen levels but you add mineral fertilizer high in nitrogen, you’ll risk damaging the ground.

You’ll also risk burning the soil if you apply too much mineral fertilizer or too frequently. The easiest way to avoid this is to read the instructions carefully before use. Mineral fertilizer can cause burning because it contains chemicals and salts, and these salts remove water from the soil and plants. Ultimately, this can dry them out.

This is also why you shouldn’t apply fertilizer at the highest temperatures of the day. If you use mineral fertilizer in the soil when the sun is at its hottest, there will be a greater risk of fertilizer burn. However, this isn’t as much of an issue with organic fertilizer.

Doesn’t Improve the Soil Structure

Although mineral fertilizer feeds the soil and surrounding plants, it doesn’t improve the overall soil structure. On the other hand, organic fertilizer does. As you apply organic fertilizer, over time, it improves elements like drainage and soil composition.

However, when you use mineral fertilizer, it dissolves over time and eventually disappears altogether. So even if you continue using mineral fertilizer for many years, it won’t positively affect the soil’s structure.

Is Organic Fertilizer Better Than Mineral Fertilizer?

Organic fertilizer isn’t better than mineral fertilizer. In many cases, mineral fertilizer is better because it’s stronger and feeds plants and soil more easily. However, organic fertilizer has the added benefit of acting as soil amendment.

The one you consider better will depend on what you’re looking for. Organic fertilizer is probably better for you if you want to liven up your lawn or plants but don’t need many extra nutrients.

However, organic fertilizer may not be the best choice if your plants need concentrated nutrients because it likely won’t be strong enough. 

Mineral fertilizer is more likely to give you greater blooms and yields if you choose the correct one and use it as advised in the instructions. At the same time, it’s also more likely to cause damage to your garden if you use too much of it.

Can You Use Organic Fertilizer Instead of Mineral Fertilizer?

You can use organic fertilizer instead of mineral fertilizer to keep your garden fed and free from synthetic materials. However, it won’t always give you the same results–you might notice smaller blooms or lower crop yields if you use organic instead of mineral fertilizer.

There are two excellent ways to determine whether or not you should use organic fertilizer instead of mineral fertilizer:

  • Examine the current state of your plants or lawn. If you aren’t currently using any fertilizer (organic or mineral), but your plants and lawn look healthy and vibrant, it should be OK for you to use organic fertilizer. If they look fragile, you should use a mineral fertilizer.
  • Do a soil test. A soil test will let you know precisely what nutrients your soil needs. If you realize that you need specific nutrients in specific amounts, you shouldn’t use organic fertilizer. However if the soil isn’t severely lacking, you can use the organic variety.

It could be damaging if you use mineral fertilizer when the soil is already healthy and nourished, so if this is the case, be sure to avoid it.

Is Mineral Fertilizer Safe for All Plants?

Mineral fertilizer is safe for all plants if you use it correctly. It works by feeding the soil essential nutrients; the surrounding plants or lawns can absorb them. Since all plants need the same essential nutrients, mineral fertilizer is an excellent choice for any garden.

However, you need to ensure you’re using an appropriate mineral fertilizer for the plants in question. For example, you shouldn’t use mineral lawn fertilizer on plants because it usually contains too much nitrogen. Plus, lawn fertilizer often contains chemicals like pesticides, which can harm plants.

So once you’ve chosen the correct mineral fertilizer for your plants and use it safely and correctly, you can rest assured.

Is Organic Fertilizer Safe for All Plants?

Organic fertilizer is safe for all plants and is an excellent choice as a general-use fertilizer. One reason organic fertilizer is so safe for plants is that the ingredients are all-natural, so there’s less chance of chemical burns (which can occur when using mineral fertilizers).

However, although you can’t necessarily burn plants and soil with organic fertilizer, you can still overuse it. If you overuse organic fertilizer, the plants may become weaker and damaged. If you purchase organic fertilizer, read the instructions to avoid over-feeding the soil.

If you’re using a homemade organic fertilizer, the amount you should use will depend on the type of matter you’re using. For example, you should apply between 1-3 inches (2.5-7.6 cm) of compost for flower beds and vegetable gardens. If you apply more than this, you’ll risk causing some damage (but likely not as severe as the damage caused by mineral fertilizer).

Conclusion

There’s a wide array of differences between organic and mineral fertilizers, all of which you should learn more about before choosing one. 

To recap, here are some of the main differences between organic and mineral fertilizers:

  • Mineral fertilizer contains synthetic materials. 
  • Organic fertilizer contains all-natural ingredients.
  • Mineral fertilizer comes in a wide variety of strengths.
  • Mineral fertilizer can cause fertilizer burn.
  • Organic fertilizer also acts as a soil amendment.

Organic fertilizer is usually better if you’re not looking for something too potent or concentrated. Mineral fertilizer is better if you do need something specific.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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