A Guide to Organic Lawn Fertilizer

Organic lawn care

Do you know your Peruvian bat guano from your liquid kelp?

If so, chances are you are a fan of organic lawn care.

Advocates for this more-natural set of lawn and gardening practices argue that if you rely on synthetic fertilizers and pesticides, your green lawn isn’t environmentally green.

“I think synthetic fertilizers have run their course,” says Nate Clemmer, CEO of Philadelphia-based Branch Creek Lawn, a producer of organic lawn care products.

When it comes to synthetic fertilizers, “People are beginning to question what they’re putting down, why they’re putting it down, and now we have alternatives,” says  Charles “Chip” Osborne, Jr., President of Osborne Organics of Marblehead, Mass., and founder of the Organic Landscape Association. As far as synthetics go, “I don’t need them. We can grow without them.”

Synthetic fertilizers made from natural gas exploded into agricultural use after WWII, boosting crop yields and feeding billions. Their use expanded to home lawn and garden care shortly after, and with the encouragement of manufacturers, conventional lawn care in the United States became a series of cyclical chemical applications.

But that has created problems. Nitrogen and phosphorus runoff from fertilizers, particularly in their fast-release form, have caused such environmental damage that 25 states have limited fertilizer use. And on an individual lawn level, synthetic fertilizers work against natural soil health.

History of Organic Lawn Care

In reaction, organic lawn care began to take root. In the early 1990s, a trio of Yale University researchers wrote “Redesigning the American Lawn,” in which they advocated for what they called “The Freedom Lawn,” a minimally maintained lawn allowing any plant to grow. No fertilizer, no watering — just an occasional mow.

“I’m not a Luddite,” the 81-year-old Bormann told an interviewer in 2003. “I recognize the use of fertilizers, pesticides and genetic engineering as being important components of how our society works. But it’s just the notion that there’s no limit to it — and if we get in trouble we’ll fix it — that concerns me.”

Over the years, as environmental damage caused by nitrogen and phosphorus runoff became clear, the concept developed. Today, any online search for organic lawn care service will find lots of offerings. There are multiple training programs and organizations for lawn care companies’ workers to learn the practice.

What Organic Lawn Care Is

Here’s what organic lawn care is:

  • At its simplest, organic lawn care is managing your lawn without pesticides or synthetic fertilizers.
  • It takes a soil-based approach to lawn care, in which soil testing is the basis for making changes. “We’re taking a ‘feed the soil’ approach as opposed to a ‘feed the plant’ approach,” Osborne says. “If you are using an organic fertilizer you are feeding the microbial life in the soil with that fertilizer and then that microbial life is breaking it down to the form the plant can use, and you are building that biomass.”  The soil, in turn, feeds the plant.
  • It requires giving up on the idea that a lawn is a monoculture of one single grass species and that your lawn will be completely free of other life.
  • Organic lawn care takes a long-range view of lawn health and looks for solutions rather than fixes. For example, if crabgrass shows up, the conventional treatment is to apply a synthetic pre-emergent weed killer in the early spring — every spring. The organic approach is to encourage a healthier lawn so that crabgrass gets crowded out. (Corn gluten meal, a byproduct of the corn milling process, is an organic weed control alternative.)

What Organic Lawn Care Is Not

Organic lawn care is not:

  • An invitation to laziness.  Simply skipping lawn maintenance won’t have the best results. The “Freedom Lawns,” for example, have been found to be less effective in preventing fertilizer pollution, because they develop big bare spots and allow runoff. Like any regimen, going organic will require an investment of time and money, so it’s wrong to think, “I do nothing, therefore I am organic.”
  • A quick fix. The tradeoff in organic lawn care is that you give up the near-instant green-up gratification that comes with synthetic fertilizers.
    It will take months — even a couple years — to change over completely from conventional lawn care to organic lawn care, says Clemmer. He likens the process to the transition a drug addict makes to sobriety. “When a lawn has been jacked up on synthetic fertilizers for years, there needs to be a transitionary period.”

Synthetic Lawn Fertilizer Advantages

Still, synthetic fertilizers have their advantages. For one, they tend to be quick-acting. The Scotts Liquid Turf Builder, for example, boasts that its quick shot of nitrogen can green up a lawn in as few as 24 hours.

They are homogenous products that break down in a predictable, consistent way, enabling a uniform application to your lawn.

Synthetic Lawn Fertilizer Disadvantages

But overuse can lead to fertilizer burn, particularly with fast-release, water-soluble formulations. Fertilizer burn leaves grass plants scorched, turning yellow or brown due to the presence of nitrogen salts. The problem occurs most often in hot weather, or when the fertilizer is not watered in.

Their runoff is bad for bodies of water. “These nutrients have been linked to eutrophication, a biological process in ponds, lakes, and streams where excessive seasonal algal growth occurs,” according to  Purdue University Agronomy-Turf Science researchers. “These blooms can make the water smell and taste bad and decrease its recreational value. In severe cases, the algae deplete oxygen levels, which may kill fish.”

They kill beneficial microorganisms in the soil that would ordinarily be working to break down nutrients into forms the grass plants can use.

Organic Lawn Fertilizer Advantages

Organ lawn fertilizers are made of organic matter that contributes to a healthy lawn.

In addition to delivering nutrients, the organic matter stays in the soil and breaks down to help improve soil structure.

They also encourage the presence of beneficial microbes whose job it is to break down organic matter into chemicals that roots can absorb.

Insect control usually isn’t an issue for a healthy lawn. With organic lawn care, homeowners expect that there will be bugs, but most of them are beneficial and feed on the pests. If there is an insect infestation can be dealt with by … more insects! Beneficial nematodes and ladybugs are among the beneficial insects that can be purchased commercially. In a pinch, there are some “biorational” pesticides, which have a low level of toxicity to the environment and their untargeted species.

While organic fertilizers can be more expensive than synthetic ones, organic fertilizers and practices reduce the overall need to apply nutrients and pesticides.

Organic Lawn Fertilizer Disadvantages

According to the Ohio State University Extension, “One major disadvantage of organic fertilizers is that they tend to be bulky compared to chemical fertilizers, so more pounds of product must be applied to deliver the same amount of actual nutrient.”

They are an inconsistent product that breaks down at different times.

They are slow to decompose, so their benefits might not show themselves for months. Fertilizer made from waste sheep wool, or example, has an extremely slow release, taking up to nine months to decompose and deliver its nutrients. “They work at Mother Nature’s speed,” says Ron Neitzel of Cleveland, whose book “The Green Wizard’s Gude” was published in February 2019. “The synthetics are able to work their way into the grass much quicker.”

And frankly, they stink — at least some of them do. Fish emulsion products can leave your lawn smelling like decaying fish, and because organic fertilizers need to be applied at a high rate to be effective, phew!

Organic Lawn Fertilizers
Organic fertilizerNitrogen (N%)Potassium (P%)Phosphorus (K%)Pounds of product needed for 1 number of N
Alfalfa pellets51220
Blood meal101010
Blood meal, steamed315033
Composted chicken manure0.50.30.5200
Composted cow manure0.50.30.5200
Cottonseed meal31133
Feather meal12008
Fish pellets77214
Kelp meal21350
Organic pellets (various ingredients)66616
Corn gluten meal100010
Seabird guano12828
Shellfish fertilizer33133
Soybean meal71314
Erth Food1.50.50.533
ReVita Compost Plus34333
These are general N-P-K values and will vary by source of product.

8 Best Practices for Organic Lawn Care

Over the years, a series of best practices have emerged for organic lawn care. Most of them are good practices no matter how you fertilize.

1. Grow the right grass. Getting a mixture of grasses well adapted to your region will mean the grass won’t have to compete as hard to succeed.

Before you plant new grass seed, lay down grass sod or overseed an existing lawn, be aware that your grass seed choice will in part set your fertilizing needs. Kentucky bluegrass, for example, is a cool season grass that demands more fertilizer.

2. Get a soil test, available through do-it-yourself or mail-in kits, through local extension offices or via commercial testing services. Amend the soil as indicated by the test.  After the initial test,  turf experts say you may skip the test for a couple of years unless there’s a reason to believe something has changed.

If your soil is lacking organic matter, you may need to add a topdressing of 1 to 2 inches of quality compost, or a compost-sand mix, before seeding.  This is especially true in new developments, where topsoil is either removed or blended with lifeless soil dug up during the construction process.

3. Aerate. Over time, soil can become compacted. Aeration with a core aerator will improve the soil to reduce that compacting and make room for new grass roots. Try to aerate when the soil is moist but not drenched the corer can reach deep into the lawn, and make several passes over the lawn.

4. Be careful with fertilizer. Don’t apply to frozen soil or rinse overspray into the sewer system. If you live in one of the 25 states where fertilizer use is restricted, know those restrictions. Your city or county may also have additional restrictions.

5. Water deeply, infrequently. Good lawn irrigation isn’t hard, if you listen to your lawn. A well-established lawn will tell you when it needs moisture. The telltale signs will vary with grass type, but curling of the blades, a dulling of color, or if footprints remain in the grass after you walk on it, it is probably time to water. A long screwdriver can also help: If it slides in easily and deeply into your soil, you can probably skip watering today. If it gets stuck after an inch or two, it’s likely time to water. Deep watering encourages a deep root system and lush lawn that acts as natural weed control.

6. Read (don’t feed) your weeds. Listen to what your weeds are telling you about your lawn, says Neitzel.

“In the organic world, Mother Nature has a plant for everything and a place for every plant,” he says. “Weeds are there to help us. They tell us conditions of the soil.” An outbreak of clover, for example, tells you the lawn is thirsting for nitrogen. The trick, he says, is to “read your weeds” — figure out why your soil allows a particular weed to thrive. Once the soil is healthy, it produces a thick lawn that starves out weeds.

7. Mow high, never removing more than one-third of the length of the grass. Proper lawn mowing, whether by yourself or a lawn care professional, will also encourage deep-rooted grass that won’t need a quick boost from a chemical fertilizer. Set your mower at a high setting and keep your mower blade sharp so the grass blades are cut, not torn

8. Mulch your clippings. One of the simplest ways to go organic is to take advantage of your natural fertilizer you are already growing: grass clippings. With few exceptions, it’s better to let mulch grass clippings decompose into your soil instead of bagging and removing it. You will return a couple of pounds of nitrogen to your soil over the course of one mowing season — probably enough to skip a fertilizing cycle.

Daniel Ray

Daniel Ray

Daniel Ray is LawnStarter.com's editor in chief. He is an award-winning writer and editor who previously was editor in chief of the personal finance websites Bankrate.com and CreditCards.com, but with 30 years of gardening experience, he's well qualified to help consumers grow a different kind of green.