Organic Lawn Fertilizer

Reprinted with permission from author, Sod Lawn

Bat guano, liquid kelp, homemade compost, and chicken manure – what do these four things have in common? If you don’t already know, this guide to organic lawn fertilizer should help you learn.

All of the ingredients listed above are things that are prized by organic gardeners the world over. There are all types of organic lawn fertilizers that will help your grass grow green and healthy without all the risks and potential side effects of synthetic lawn fertilizer.

Keep reading to learn everything you need to know about organic lawn fertilizer – and how you can use it to your advantage on your existing lawn and garden or when you are caring for existing or new sections of sod. 

What is Organic Lawn Fertilizer?

Organic lawn fertilizer sounds like a complicated science fiction term, but really, it’s just fertilizer that will allow you to manage your lawn and provide it with the nutrients it needs without applying chemicals. Organic lawn foods feed soil life, including beneficial microbes and bacteria, without depleting them, as is the case with synthetic fertilizers. They can also help your lawn survive mowing and other “traumas” with ease.

According to the Organic Lawn Care Manual by Paul Tukey, “the word organic describes any compound from any natural or laboratory source that contains a carbon molecule.” However, for the sake of organic gardening, “products and soil amendments within the system must be derived for plants, animals or minerals; actions should be considered for their impact on soil, water, and air quality and on the health of the earth.”

How Does Organic Fertilizer Compare to Non-Organic?

If you’re curious about how organic fertilizer stacks up, either because you’re new to the world of fertilizers or you’ve been using synthetic fertilizers your whole life and are ready to make the switch, consider these benefits and disadvantages of each – and of using fertilizer in general.

Benefits of Lawn Fertilizer

Although some lawns might have that magical ratio of nutrients they need to grow lush and healthy, in most situations, that’s not the case. Regular feedings are the best way to care for your lawn.

When lawns are fertilized with the nutrients they need most (primarily nitrogen, but also phosphorus and potassium), they can grow strong, healthy plant roots and blades. Fertilizing just once won’t cut it either, as lawns will leech nutrients over time.

A fertilized lawn will exhibit improved overall growth and more resistance to pests, diseases, and weeds. Fertilizing can also prevent soil erosion, as it encourages the growth of thick turf that is less likely to cause soils to become depleted during heavy rain and wind.

Advantages of Synthetic Lawn Fertilizer

If you’ve ever used a synthetic lawn fertilizer (Miracle Gro is an example!) you’re probably already familiar with its benefits. They are usually quick-acting, working to provide nutrients in as little as 24 hours. These fertilizers are homogeneous in their composition and break down in a consistent, predictable, and uniform way.

They’re also readily available. You can pop out to your local lawn and garden store and find whatever nutrients you  need for your lawn, right there on the shelf.

Disadvantages of Synthetic Lawn Fertilizer

Of course, there are several drawbacks to using synthetic lawn fertilizer that you need to know about.

One is that overusing synthetic fertilizers, which tend to be heavy in nitrogen salts, can lead to a condition known as fertilizer burn. This is especially true with fertilizers that consist of quick-release, water-soluble formulations. Fertilizer burn can cause your turf to turn brown or yellow and can ultimately kill your plants, particularly if you apply fertilizer during hot weather or do not water it in.

Chemical-based fertilizers can also kill the beneficial soil microorganisms that live in your soil. These beneficial soil microbes work hard to break nutrients down to make them more accessible to your plants, meaning overuse of synthetic fertilizers can have the opposite effect of what you desire.

Finally, synthetic fertilizers are well-documented in the harm they do to bodies of water. They can cause an excess growth of algae and even kill fish.

Advantages of Organic Lawn Fertilizer

More gardeners and homeowners are looking to organic lawn fertilizer as they seek to add nutrients to their lawn in a safer, affordable way. Organic lawn fertilizers are organic matter that contributes to healthy soil.

When these fertilizers are added to the soil, the matter stays in the soil and breaks down slowly. This means that organic lawn fertilizers can improve your soil quality as well as add nutrients, something that synthetic fertilizers simply can’t do. They can encourage the presence of helpful microbes rather than kill them.

In a healthy lawn, insect control isn’t usually an issue, but using an organic fertilizer is a better option in this case, too. While organic fertilizers can sometimes be more expensive than synthetic ones, they need to be applied less often – as do pesticides – so you’ll ultimately save more money in the long run.

Disadvantages of Organic Lawn Fertilizer

As with anything, there are a few disadvantages to using organic lawn fertilizer, too.

The biggest one is that organic fertilizers tend to be bulkier than chemical fertilizers. What does this mean? Not only do the products break down at various times and are slower to decompose, but they also require a higher application rate (you’ll have to apply more pounds of product to deliver the same amount of nutrients).

Finally, while there are plenty of stink-free options out there, some organic fertilizers – like manure – quite frankly, smell!

Is Organic Fertilizer Safe For Pets?

Although organic fertilizers are usually derived from more natural plant and animal byproducts, it’s important to note that some organic fertilizers are still not safe for pets and can cause harm.

Make sure you are careful about reading labels and apply your fertilizer in areas where your pets can’t access them – yes, even if you’re using an organic fertilizer! You can read more about fertilizers and other lawn care products and their risks for pets here.

Choosing the Best Organic Lawn Fertilizer for Your Lawn

Choosing the best organic lawn fertilizer for your lawn will likely come down to first figuring out what kinds of nutrients your soil needs. While most organic lawn fertilizers offer balanced ratios of NPK, something we’ll discuss in more detail below, some offer more of one nutrient than another.

Knowing exactly what nutrients your lawn needs is the first step in selecting the right organic fertilizer. Conduct a soil test by taking a soil sample and sending it off to your local cooperative extension. You can also purchase an at-home soil test kit. Regardless of the option you choose, conducting a soil test will help you determine the pH of your lawn as well as whether you need an amendment to help improve the soil’s structure and nutrient content.

You will also need to consider the type of grass you are growing. According to The Lawn Bible by David R. Mellor, “Out of the over 10,000 species of grass, only about 50 species can produce a lawn,” – and of those 50 species, each has its own unique nutrient needs.

What is NPK?

Do any amount of research on organic or synthetic fertilizer, and NPK is a term you will likely see again and again.

This acronym refers to the three macronutrients that are necessary for plant growth. N, or nitrogen, helps support leafy green growth. Phosphorus, or P, provides for a strong root system, while potassium, or K, helps to keep plant growth healthy and balanced, supporting their overall growth.

When found on a fertilizer bag, you’ll see these three nutrients listed in that order – NPK. There will usually be a percentage listed per pound as well, with many labels helping you calculate the amount of NPK per 1000 square feet.

Of course, one of the major benefits of using organic fertilizer is that it provides other micronutrients in addition to the macronutrients listed above. An organic fertilizer might provide all the NPK you need along with things like calcium, magnesium, and sulfur.

Application Type

When you are looking for an organic lawn fertilizer, you’ll usually see two types of fertilizers: dry and liquid. Here are the differences so you know which one is right for you.

Dry Fertilizer

A dry fertilizer is one that is incorporated into a granular form. It’s cheaper to buy in bulk and easy to store for long periods of time, since it doesn’t settle out or salt out in cold weather. It’s best for when you need to apply fertilizer pre-planting and there are lots of slow-release options available.

Liquid Fertilizer

Liquid fertilizer, as you might expect, is bottled and stored in a liquid form. It is easier to apply, blend, and handle, and can be applied more evenly than dry fertilizer (a bonus if you need to apply fertilizer to a large area). You can use it both before planting as well as during the season.

Types of Organic Fertilizers

Not all organic fertilizers are made alike! Here are some of the most common organic fertilizers you might see for sale.

Animal-Based Fertilizer

Chances are, if you’ve heard of organic lawn fertilizer or considered using it on your lawn, you’ve likely thought of animal-based fertilizers. These are typically good for the soil, helping to decrease water stress and improve the soil’s water retention and drainage and its nutrient-holding capacity. Here are some of the most common options.

  • Fish emulsion: Fish emulsion (or fish poop, for the less sophisticated crowd!) is a good option when nitrogen is in high demand. It has an NPK ratio of 12-0-0.
  • Blood meal: You guessed it – blood meal is blood, plain and simple. Also high in nitrogen, it has an NPK ratio of 10-1-0. Feather meal is another high-nitrogen option.
  • Animal manure: Animal manure varies in its NPK since you can use manure from several types of animals, including chicken, cow, rabbit, and sheep (experts advise against using manure from cats, dogs, and pigs, as they can harbor dangerous diseases). Composted chicken manure (as well as many other types of poultry manure) contains an NPK of 0.5-0.3-0.5 while composted cow manure comes in almost exactly the same.
  • Fish meal: Fish meal, made up of ground-up fish parts like bone meal, is another good option for fertilizing your lawn in a more natural way. It has an NPK of 5-2-2.
  • Shellfish: Last but not least is shellfish fertilizer. It has a high NPK of 3-3-1.

Plant-Based Fertilizer

There are several kinds of plant-based fertilizers you can use on your lawn as well. They offer many of the same benefits of animal-based fertilizer.  Some to consider include:

  • Alfalfa and soybean meal: You can usually find this kind of fertilizer both in a pelletized and ground format. Alfalfa pellets have an NPK of 5-1-2 while soybean meal contains more nitrogen with a ratio of 7-1-3.
  • Compost: Compost is the organic gardener’s favorite tool, since you can make it for free and with very little effort at home. The NPK can vary depending on which ingredients you choose to include in your compost but it’s generally considered to be a very balanced source of organic fertilizer for your lawn.
  • Cottonseed meal: Cottonseed meal has an NPK of 3-1-1 on average.
  • Molasses: Molasses is one of the more expensive organic lawn fertilizer options you might consider. However, it has an NPK ratio of 0.7-0-5.32.
  • Legume cover crops: The NPK of legume cover crops varies depending on what kind of plant you decide to sow. However, they tend to be high in nitrogen and have the added benefit of improving soil structure (particularly for heavy clay), since you’ll tell them when you’re ready to plant. An example of a legume cover crop is winter peas.
  • Green manure cover crops: As with legume cover crops, the NPK of these fertilizers will vary depending on the plant you decide to grow. Some examples include annual ryegrass, rapeseed, and buckwheat.
  • Kelp seaweed: Kelp seaweed is another plant-based dose of fertilizing goodness you can consider. It has an NPK of 2-1-3.

Of course, this list is not exclusive. Some other organic lawn food that people use include natural ingredients like grass clippings, shredded leaves, and bark.

Mineral-Based Fertilizer

If you know that your garden is deficient in a certain mineral or micronutrient, like calcium or magnesium, you might want to consider using a mineral-based fertilizer instead. This will provide a more direct source of nutrients.

  • Calcium: Calcium can be applied in its whole form, with options including things like calcium nitrate. This can help with cell formation.
  • Epsom salt: Epsom salts can help provide things like magnesium, sulfur, and more to your garden. It has an NPK of 20-20-20.
  • Greensand: Also known as glauconite, greensand is a mineral mined from the ocean floor especially to be used as fertilizer. It has an NPK of 0-1-6 and also contains trace minerals like iron and magnesium.

How to Make DIY Organic Lawn Fertilizer

There are several DIY organic lawn fertilizers you can make. One of the most popular options requires the use of beer, soda, soap, ammonia, and mouthwash.

Combine a can of soda (non-diet – the sugar is what helps microbes in the soil thrive), a can of beer, and half a cup of dish soap (make sure it’s not antibacterial). Add half a cup of ammonia and half a cup of mouthwash along with ten gallons of water. Apply to a sprayer, and apply to your lawn before or after seeding. It’s as easy as that!

Where to Buy Organic Lawn Fertilizer?

You can purchase super natural lawn fertilizer anywhere you might purchase synthetic fertilizers, including:

  • Lawn and garden stores
  • Mass online retailers (such as Amazon)
  • Hardware stores
  • Department stores
  • Farm supply stores
  • Places where you might buy lawn mowers or mower equipment

You can also purchase many kinds of organic lawn fertilizers (like manures) from local farmers. Many can even be made or harvested for free at home, like compost.

When Should You Apply Organic Fertilizer?

The best time to apply organic lawn fertilizer will vary depending on the type of grass you are growing. Usually, regardless of the grass type, you will need to apply fertilizer several times throughout the year and particularly during the growing season.

A warm-season grass like zoysia, Bermuda, or centipede needs to be fertilized two to four times each year, ideally at the start of spring and the end of the summer as well as several times throughout the summer months.

Cool-season grasses, on the other hand (these include species like fescue and ryegrass) only need to be fertilized right after the lawn comes back after being dormant over the winter as well as at the beginning of the fall. Unlike warm-season grass, cold season grass should not be fertilized during the summer.

For all kinds of fertilizer and grass types, do so first thing in the morning or at the end of the day, in the evening. This will prevent your grass from burning in the hot summer sun.

How to Apply Organic Lawn Fertilizer

Application instructions for organic lawn fertilizer will vary depending on what kind of fertilizer you are using and whether it is granular or liquid.

With a liquid fertilizer, you will often need to combine it with water and put it in a backpack or hand pump sprayer. You can then spray it directly onto your lawn. Some liquid fertilizers come in packages that make them attachable to a hose for easy application.

Granular fertilizers, on the other hand, are meant to be applied with a granular spreader. Dampen your lawn (either with a hose or natural rainfall) before applying the granules and be sure to water afterward, too. This is essential when caring for a new lawn or sod!

For all fertilizers, check the instructions on the package to see if they need to be mixed before they are applied to your lawn.

Images from iStock/Sasiistock (main), Anuphong Panyamoon (NPK), amyleighcook (dad with kids). 


Kym Preslar

Kym Preslar is a bit of a gardening and home improvement fanatic. She’s been working on her garden for over 5 years and loves writing about everything landscape-related. Whether it’s keeping care of sod or the greenhouse, she’s been there and done it all. Currently, she’s enjoying her time working at SodLawn as their Content Manager.

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