Whoever said, “The grass is always greener on the other side” probably wasn’t using the right stuff. When it comes to keeping a yard in top condition, all you really need is the best lawn fertilizer for your climate and conditions, and a few dates circled on the calendar. Once you’ve determined what’s ideal, simply apply as instructed and follow up as directed on the package. This guide will teach you the fertilizer fundamentals and offer reviews of some of the highest-rated products on the market.
- BEST OVERALL: Milorganite Slow Release Nitrogen Lawn Fertilizer
- BEST ORGANIC: The Andersons 7-1-2 Innova Organic Fertilizer
- BEST LAWN STARTER: Scotts Turf Builder Starter Food for New Grass
- BEST WEED AND FEED: Scotts Turf Builder Weed And Feed
- BEST FOR GREENING: Ironite Mineral Supplement/Fertilizer
- BEST FOR THICKER GRASS: Safer Brand Lawn Restore Fertilizer
Before You Buy Lawn Fertilizer
With the rise of lawncare culture over the past century, a stream of science and marketing has arisen, promising ”the perfect lawn.” Use caution. While these truly amazing products can support a beautiful, healthy patch of grass, the same products used improperly can kill the grass, make you sick, and aggravate a host of environmental problems.
Before buying and applying lawn fertilizer, find out what kind of fertilizer and how much your grass needs. A soil test, either a do-it-yourself kit or a mail-in packet through your local extension service, will provide the information you need. Avoid any temptation to apply more than the test results recommend. Doing so could screw up the soil chemistry, and maybe worse.
What to Consider When Choosing Lawn Fertilizer
Shopping for lawn fertilizer is anything but intuitive. Just ahead, find out more about what your lawn really needs, and the best way to provide it.
You may have noticed three digits printed on lawn fertilizer labels. Known as the NPK ratio, the numbers stand for the percentage of basic nutrients (N for nitrogen, P for Phosphorus, K for Potassium) the fertilizer contains. If a fertilizer’s NPK ratio is 12-0-10, for example, it contains 12 percent nitrogen, no phosphorus, and 10 percent potassium.
Generally speaking, nitrogen helps plants stay green, phosphorus promotes root growth, and potassium guards against drought and disease. Depending on the type of turf you have, the soil’s native chemistry, and the climate where you live, one combination will be better than others. The best way to determine the exact needs for your lawn is by beginning your fertilization program with a soil test, and then finding the fertilizer that best fills in what’s missing.
Organic vs. Synthetic
Once you ascertain your best NPK number, it’s time to decide between a synthetic or organic fertilizer.
- Synthetic varieties are engineered from minerals, gasses, and even waste with the intent of delivering fast results—sometimes within a matter of days. The downsides to synthetic fertilizers are their reputation for “burning” (i.e., killing) grass if used in too heavy-handed a manner. There can also pose environmental damage and health risks if they leach into the local water supply.
- Organic fertilizers are made from living organisms—anything from cottonseed or peat moss to bat guano and blood or bone meal. They can take a bit longer to work their magic—it’s often a few weeks before results are visible. Although they require a bit of patience, the environmental and health risks are low.
There are two fertilizer formulas: liquid and granular. Liquid fertilizer, which comes as either a fluid (requiring dilution in water) or a powder (to which water should be added), tends to require more frequent application than granular. It can also pose an environmental risk if it contaminates the local water supply in large amounts, leaking lead, cadmium, and arsenic via storm drain runoff and causing algae blooms as well as long-term public health risks. That said, it’s an effective way to see quick results, so it’s only recommended when you need truly rapid results and can use it sparingly.
Granular fertilizer tends to operate in a slow-release fashion, taking up to a month or longer to deliver results but requiring less-frequent follow-up. It also poses far less of a health risk overall, so it’s generally a better option unless you’re not willing to wait a few weeks for your yard to green up.
Fast vs. Slow Release
The decision between fast and slow-release fertilizer formulas comes down to grass metabolism. Two instances when fast release lawn food can be beneficial are early spring and when planting a new lawn. A quick dose of nitrogen fertilizer helps overwintered grass produce new leaves early in the season which help it to grow more roots faster. Similarly, a quick-release lawn starter can help young grass seedlings or newly installed sod become established quicker.
On the other hand, slow-release lawn food is best for long-term maintenance. This type of plant food ensures a steady supply of the right nutrients throughout the season. Slow-release lawn fertilizer is like a meal for the lawn, but fast release is more like a snack.
Most warm and cool season grasses share many of the same nutritional requirements. They thrive on a steady supply of nitrogen throughout the growing season to support fast-growing foliage. Phosphorus may not be necessary, and should only be applied based on the guidance of a soil test. Potassium needs to be replenished regularly to support drought resistance and overall health. The usual, healthy ratio is on the order of 4-0-2.
Two grass types that buck this trend are centipede and St. Augustine grasses. These warm climate species consume greater amounts of potassium than other grasses. They need roughly equal amounts of nitrogen and potassium, but near-zero phosphorus. Look for 15-0-15, or something similar, for these grasses.
Our Top Picks
If you need a great fertilizer to build a strong, healthy lawn, keep reading. In the reviews ahead, we share more product information about our top picks and why we considered them to be some of the best lawn fertilizers available.
Milorganite has been a staple in the lawn fertilizer industry since it was originally released in the 1920s. This recycled lawn food is derived from heat-treated, nutrient-rich microbes that filter and process organic matter in municipal wastewater. The fertilizer boasts a 6-4-0 NPK analysis, with 2.5 percent iron that promotes deep greening. One application feeds for 10 weeks, and it does not need to be watered in. The 32-pound bag covers 2,500 square feet.
In addition to delivering consistent, deep greening nourishment to the lawn, Milorganite is known to deter garden pests like deer and rabbits. But one cause for caution is that, as with other biosolids-based fertilizers, it contains traces of PFAS – so-called forever chemicals with links to a variety of chronic health problems.
- NPK Ratio: 6-4-0
- Weight: 32 pounds
- Coverage: 2,500 square feet
- Derived from recycled waste material
- Feeds gradually, reduces nutrient pollution
- 2.5 percent iron for deep greening
- Value price point
- Contains measurable levels of polyfluorinated chemicals (PFAS)
- Contains 4 percent phosphorus, which many soils do not need
Get Milorganite at Ace Hardware, The Home Depot, and Lowe’s.
The Andersons Innova feeds lawns at a slow, steady pace with 7-1-2 NPK content and amino acids. The plant-based formula does not contain worrisome biosolids, manures, recycled waste, or animal parts. The non-burning granules prevent damage, and are engineered for low dust, so that they are easy to apply without sneezing. The 40-pound bag feeds up to 5,600 square feet of lawn.
Innova 7-1-2 is OMRI listed for use in certified organic operations, with a low-runoff formula that is safe to apply near waterways. It stimulates a healthy soil ecosystem by supplying easily digestible carbon to fuel soil microbes. This product is as close as it comes to the organic ideal.
- NPK Ratio: 7-1-2
- Weight: 40 pounds
- Coverage: 5,600 square feet
- OMRI listed, USDA BioPreferred
- Contains no biosolids, manure, composted waste, or animal components
- Slow release pellets
- Low odor
- Premium price
- Bulkier and heavier than non-organic fertilizer
Get The Andersons Innova Organic Fertilizer at Amazon, A. M. Leonard, and Walmart.
When you are starting a new lawn, whether by seed, sod, or plugs, the right soil nutrition is essential. Scotts Turf Builder 24-25-4 Starter delivers a strong boost of phosphorus for rapid root establishment and nitrogen for healthy foliage growth up to 70 percent faster than unfertilized lawn. The small granules are designed to dissolve rapidly for quick delivery through the lawn’s six-week germination and establishment phase. The 15 pound bag feeds 5,000 square feet of new lawn.
This conventional Scotts fertilizer offers powerful plant nutrition in a compact, lightweight package. It works fast, but can contribute to runoff pollution when used incorrectly. Soil preparation is a critical step to maximize the benefit of the fertilizer and eliminate nutrient runoff.
- NPK Ratio: 24-25-4
- Weight: 15 pounds
- Coverage: 5,000 square feet
- Formulated for extensive root development
- Ideal for new newly seeded or sodded lawns
- Establishes grass 70 percent faster than unfed lawns
- Lightweight and affordable
- High phosphorus content may not be necessary for all soils
- Requires soil preparation to prevent nutrient runoff
Get Scotts Turf Builder Starter at Amazon, Ace Hardware, and The Home Depot.
For a pristine lawn with less work, Scotts Turf Builder Weed and Feed takes care of two lawn maintenance tasks at once. It contains rapid release 28-0-3 fertilizer to nourish the grass, and 2,4D herbicide to kill broadleaf weeds like dandelions and clover. The 14.29 pound bag treats 5,000 square feet of grass.
It’s easy to apply this product, but doing so is time-sensitive. The lawn must be wet from dew, recent rain, or irrigation at the time of application so that the dry weed killer component adheres to weed leaves. No rain should be in the forecast and no irrigation for the first 24 hours after application, after the wait period it should be watered in. Keep pets and people off the treated area for 24 to 48 hours.
- NPK Ratio: 28-0-3
- Weight: 14.29 pounds
- Coverage: 5,000 square feet
- Dual action product saves time and money
- 28-0-3 fertilizer for grass maintenance
- 2,4D broadleaf weed killer
- Compact and lightweight package
- Time and water sensitive
- Not safe for young grass seedlings
- No people or pets on the lawn for 24-48 hours after application
Get Scotts Turf Builder Weed And Feed at Amazon, Ace Hardware, and The Home Depot.
When the grass doesn’t look quite right, it may not be lacking in nitrogen, phosphorus, or potassium. The only way to really know is by getting the soil tested, but a pale green or yellowish hue often indicates iron deficiency. Ironite, with 12 percent soluble iron, addresses the root cause of iron deficiency without risking over-fertilization. The low levels of nitrogen and potassium help the grass absorb and metabolize iron for deep greening and lasting results. The 15-pound bag covers 5,000 square feet.
Granular Ironite goes on like other lawn fertilizers, but be sure to use caution around concrete and stonework because spills develop into dark stains. Water it in immediately after application for best results.
- NPK Ratio: 1-0-1
- Weight: 15 pounds
- Coverage: 5,000 square feet
- Treats iron deficiency
- Prevents over fertilization
- Easy-to-apply granular formula
- Soil should be tested for iron deficiency before applying
- Spills can cause staining on concrete and stone
Get Ironite at Amazon, Ace Hardware, and The Home Depot.
Difficult growing conditions can cause a snowball effect, where declining grass leads to depleted soil. When that happens, it takes a combined effort to turn things around. First identify and address the origin of the problem, often fungus, insects, or competition from a growing tree, then treat the area with Safer Brand Lawn Restore Fertilizer. The blend of organic plant food ingredients is designed to increase soil biological activity while it nourishes the grass. The 20 pound bag treats 5,000 square feet of lawn.
Safer Brand Lawn Restore is derived from natural fertilizer ingredients including feather meal, soybean meal, blood meal, alfalfa meal, molasses, and sulfate of potash. The nutrients are not water soluble, but instead are released by the action of soil-building microbes. So, it builds soil as it feeds plants while protecting the environment from the effects of nutrient runoff.
- NPK Ratio: 9-0-2
- Weight: 20 pounds
- Coverage: 5,000 square feet
- Builds soil organic matter
- Strengthens weak grass
- Easy to apply
- Safe for the environment
Get the Safer Brand Lawn Restore Fertilizer at Amazon, Ace Hardware, and The Home Depot.
Since potent, fast-acting lawn foods come with the inherent risks of burning the lawn or polluting the environment, we recommend taking a natural approach. Our best overall pick, Milorganite fertilizer, has been popular among professionals and homeowners alike for more than a century. It’s an affordable fertilizer that feeds the soil for steady plant growth and a deep greening effect. The Andersons organic fertilizer is another safe, easy to apply option that includes additional soil-enhancing ingredients, and leaves out questionable products like biosolids and animal-derived ingredients.
How We Chose the Best Lawn Fertilizers
The lawn fertilizer industry is flush with specialty products for every conceivable need. Unique formulations abound for winterization, spring green-up, summer maintenance, weed and feed, lawn starter, northern and southern grass formulas, and so much more. We wanted to cut through the noise and recommend lawn foods that would be broadly useful for the widest range of lawns, including warm and cool-season grasses and acid-loving lawns.
Effective fertilizers provide for the ongoing needs of the targeted plant. For most lawn grasses, without considering the existing soil chemistry, an NPK ratio of about 4-1-2 is necessary for healthy growth. However, since most soils in North America hold an adequate amount of P, we decided to start our search with 4-0-2 equivalent fertilizers (8-0-4, 12-0-6, etc). This was not an absolute, but more of a guide.
As for formulations, we leaned into organic and natural products for a couple of reasons. Organic fertilizers are non-burning, promote healthy soil ecology, minimize nutrient runoff, and provide an extended, steady feed. Non-organic fertilizers can do these things as well, but as a category, organics do so with a high level of consistency from product to product. Plus, it’s rare that a lawn actually needs a quick burst of plant food, even more so with lawns that have been consistently fed.
Our final list included organic selections for regular maintenance and repair, along with non-organics for unique situations where their targeted use solves specific problems.
Tips for How to Fertilize Your Lawn
The first and most important step in fertilizing the lawn is to find out what the lawn is lacking. By testing the soil chemistry, you quickly uncover nutrient imbalances that can be corrected with targeted applications. Otherwise, you risk overapplying nutrients that are already present or neglecting a nutrient deficiency. Once you have the test results in hand, then match the results to the best available fertilizer.
- For even coverage, apply with a fertilizer spreader.
- With the spreader calibrated at half the recommended rate, apply in parallel lines going one direction, then again in lines running perpendicular to the first application.
- Avoid broadcasting fertilizer onto pavement or landscape beds.
- Blow or sweep fertilizer off of pavement immediately after application.
- Apply fertilizer ahead of rain or run sprinklers within 24 hours after application.
See answers to the most commonly asked questions about lawn fertilizer below.
Q: When is the best time to fertilize your lawn?
For cool-season grasses, like tall fescue and Kentucky bluegrass, fertilize when the soil reaches 55 degrees, or when it has begun active growth. For warm-season grasses like bermuda grass, zoysia, and centipede grass, fertilize when the grass has turned at least 50 percent green after winter dormancy.
Q: How often should you fertilize your lawn?
Feeding frequency depends on the fertilizer formula, type of grass, climate, weather, and soil nutrient levels. Overfertilization is a far greater risk to the lawn itself and to the environment than not fertilizing. With organic lawn fertilizers, two applications are typically adequate, unless directed otherwise by soil test results.
Q: What is the best ratio for lawn fertilizer?
The best way to know what your lawn needs is to test the soil. Avoid using balanced analysis plant foods like 10-10-10 or 15-15-15 fertilizer for lawns. Although these products hold some of the nutrients that grass needs, they do not offer them in the right amounts. Instead, use lawn fertilizer with an analysis that equates a 4-0-2 or 4-1-2 ratio.
Q: What is a natural lawn fertilizer?
Natural lawn fertilizers are made with animal and/or plant byproducts as the nutrient source, rather than mined minerals or chemical products. The nutrient analysis of natural fertilizer tends to be lower than that of conventional fertilizer, but natural products offer additional benefits such as increasing soil organic matter, boosting beneficial soil microbes, providing for an extended feed, and minimizing nutrient runoff.