Organic or Synthetic Fertilizer: Which One’s Better?

The quest for the perfect lawn involves dedication—and maybe a few doses of fertilizer. But before you get to spraying lawn fertilizer over your grass, you’ll need to decide between organic and synthetic fertilizer. Let’s put this debate to an end once and for all.

What Is Fertilizer?

First, let’s take a moment to talk about the birds and the bees. Contrary to its name, lawn fertilizer doesn’t actually fertilize plants. Instead, lawn fertilizer:

• Supplies much-needed nutrients to plants

• Fights off weeds and pests 

• Prevents diseases caused by fungi and insects. 

There are many types of fertilizers available on the market, with some inorganic or synthetic and some organic. Synthetic fertilizers are manufactured using minerals, inorganic materials, and other sources, while organic fertilizers come from kitchen scraps, microbes, and other organic waste.

What’s in Lawn Fertilizer?

There are three main nutrients found in lawn fertilizer, called macronutrients: nitrogen, phosphorus, and potassium. Plants need these nutrients to thrive, and you’ll find fertilizers prioritize them over all other nutrients. You might even see the acronym “N-P-K” on your fertilizer package to show that each of these key nutrients is present in the fertilizer. 

Here’s how each one works to help your plants:

• Nitrogen (N): Plants need nitrogen for four reasons; for chlorophyll, which plants need to turn the sun’s energy into food and carbon dioxide; for amino acids, which are the main building blocks for protein; for metabolism; and their DNA health.

• Phosphorus (P): Plants need phosphorus to harvest solar energy to grow, mature, and reproduce.

• Potassium (K): Potassium helps plants metabolize nitrogen, exchange water, and grow.

Other macronutrients that you might find in your fertilizer include calcium, magnesium, and sulfur. Micronutrients are also essential to plant life and may be added in smaller quantities. These include iron, zinc, and boron.

Synthetic Fertilizer vs. Organic Fertilizer

If you’re planning a do-it-yourself fertilization project, you’ll need to decide whether you want to use synthetic or organic fertilizer.

To help you with your decision, consider the pros and cons of synthetic and organic fertilizers:

Synthetic Fertilizers

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Synthetic fertilizers have been popular for decades and continue to be the number one choice in most conventional farms. With that said, here are some benefits and disadvantages to using synthetic fertilizers.

Pros:

• Fast-acting, nutrients absorbed quickly

• Precise results based on specific engineering and testing

• Easy to distribute in yard

• Low cost

Cons:

• May hinder microbial growth 

• Over-application of fertilizer causes lawn burn, contaminates groundwater

• Can contaminate groundwater and lead to water pollution

• Releases nutrients unevenly

• Does little to improve soil quality

Keep in mind, though the biggest concern with synthetics is runoff, if you treat your yard properly with synthetic fertilizers, it shouldn’t be a problem.

Organic Fertilizers

Photo: Khaligo/ Adobe Stock

Some homeowners prefer a more organic option out of concern over the environmental impact synthetic fertilizers can have on the soil and water sources. All-natural fertilizers are blended with plant and animal matter, such as manure, compost, alfalfa meal, corn gluten, and even bat guano, so they’re free of synthetic chemicals. 

Here are the benefits and disadvantages of using organic fertilizer in your lawn:

Pros:

• Promotes long-term soil and plant health 

• Supplies food for important microorganisms and earthworms

• Safer overall for pets, kids, and the environment

• Retains water well

• No harmful contaminants

• Supports worm and microbial life

Cons:

• Slow-release and results

• May require multiple applications

• Products differ widely

• Imprecise results

Synthetic vs. Organic Fertilizer Costs

Another factor that plays a role in choosing between synthetic and organic fertilizers is the cost. Synthetic fertilizer is more affordable than organic fertilizer. Expect to pay somewhere between $25 to $80 to fertilize an 8,000-square-foot yard using synthetic fertilizer. 

On the other hand, organic fertilizer costs around $50 to $95 for the same-sized plot of land. Keep in mind that you’ll pay more for some kinds of synthetic fertilizers than you would others. Liquid synthetic fertilizers cost slightly more than granular fertilizers, for instance.

Which Fertilizer Is Best for Lawns?

The jury’s in on which fertilizer is best for lawns. In short, it depends. Here are a few questions you can ask to help you decide on whether synthetic or organic fertilizer is right for you:

• How much are you willing to spend on fertilizer? If you’re hoping to save a little money, go for synthetic fertilizer. If you don’t mind the investment, choosing organic fertilizer will benefit you more over time.

• Do you want a simple fix to your yard or a long-lasting soil enrichment? Synthetic fertilizer will make your yard look green and vibrant, but it won’t do much to the quality of your soil or the microbes living in it. If you want to enhance your soil, opt for organic fertilizer.

• Are you adding compost to your yard? You might not need organic fertilizer if you’re already enriching your soil with nutrient-rich humus. Synthetic might be a good choice.

• Does your property have a shoreline or close to a body of water? Water contamination from synthetic fertilizer poses a greater threat to land next to water sources.

Hybrid Fertilizers: Best of Both Worlds

Who says you have to choose between one or the other? If you’re hoping to reap the benefits of organic and synthetic fertilizers, there is another option for lawn maintenance: hybrid fertilizers. 

Hybrid fertilizers contain mostly organic materials, but they’re also blended with synthetic nitrogen to help boost plant growth. Could this be the answer to the battle between synthetic and organic fertilizers? It just might!