Maintaining a healthy lawn means choosing the best fertilizer for your grass type, climate, and lawn conditions. Although there are lots of lawn fertilizers to choose from today, you can narrow down the selection by opting for the best fertilizer for your grass and keeping the following information in mind. The right grass fertilizer for your cool or warm season grasses will help you achieve a healthy lawn along with a proper lawn care routine.
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Best Lawn Fertilizer Product by Type
Consider using these best lawn fertilizers for your grass. Most lawns can benefit from a quick-release fertilizer or slow-release fertilizer with the right nutrients.
Best Overall Lawn Fertilizer: The Anderson’s Fertilizer 24-0-8
It’s no secret that we’re big fans of The Anderson’s products. In fact, their 21-0-10 with 0.15% Dimension is our #1 pre-emergent herbicide + fertilizer combo, and this 24-0-8 lawn fertilizer is no exception.
First, it contains N-(n-butyl) thiophosphoric triamide (Fortify-N) which helps limit nitrogen loss in the soil. Next, it contains iron which helps make your grass “pop” green. And lastly, it does not contain any phosphate.
No phosphorus is important (at times) for several reasons. For “No Phos” states like Massachusetts, this lawn fertilizer is ideal. In order to apply a lawn fertilizer with nitrogen, potassium, and phosphorus in these states, you need a soil test indicating a lack of phosphorus which will prohibit/limit grass growth, or at the time of planting grass seed.
Next, this granular fertilizer it will not force root growth. Particularly in the warmer months when cool-season lawns begin to slow down, forcing more growth with NPK is not recommended.
Studies have also shown that when urea nitrogen was treated with NBPT, treated areas had much more chlorophyll content than untreated areas. This, combined with the 2% Iron (Fe) results in a much greener turf than other lawn fertilizers.
This 50 lbs. bag of lawn fertilizer, applied at 3.1 lbs. per 1,000 sq. ft., will cover 16,100 square feet and deliver 0.75 lbs. of Nitrogen per 1,000 sq. ft., also making it a great value. Perfect for cool-season lawns (Kentucky bluegrass, tall fescue, perennial ryegrass) and warm-season lawns (Bermuda grass, St. Augustine, Zoysia grass).
- Spreads evenly in a fertilizer spreader
- It contains iron for extra greening
- Limited availability
Best Starter Fertilizer: 12-12-12 Starter Fertilizer
Yard Mastery “Triple 12” is our #1 starter fertilizer. The even ratio of N-P-K is ideal for lawns that need to “wake up” in the spring, or specifically at the time of seeding or overseeding new grass.
The quality of these macronutrients is very high. The 12% nitrogen is in the form of ammonium sulfate, and 12% potassium in the form of sulfate of potash (SOP) which is definitely the most preferred type of potassium for its low salt index. And the 12% phosphorus will help build strong roots.
This granular fertilizer also contains “Bio-nite” which is a form of biosolids (like Milorganite or Bay State lawn fertilizers) and 3% iron which is going to make your turf green-up pretty quick.
Note: the recommended bag rate is 3 lbs. per 1,000 sq. ft. which covers 15,000 total sq. ft. However, we apply closer to 4 lbs. per 1,000 sq. ft. (12,500 sq. ft. yield) as the total nitrogen applied at this rate is almost 0.5 lbs. per 1,000 sq. ft.
- Contains biosolids (Bio-nite)
- Even distribution of macros
- Also for warm-season grasses
- Inconsistent prill sizes
Best Organic Fertilizer: Organic Lawn Food by Jonathan Green
For a healthy lawn, organic fertilizer is crucial. And our No. 1 choice is Jonathan Green Organic Lawn Food. It has food-grade organics such as feather meal, soybean meal, and blood meal. Plus calcium carbonate and sulfate of potash (SOP).
We also like Safer Brand Lawn Restore and Innova 7-1-2, but only if this Jonathan Green natural lawn fertilizer is not available.
Jonathan Green is my go-to organic fertilizer in my own backyard for my kids and dog.
- Homogenous blend for all grass types
- Safe for kids and pets
- Takes more time to see visual effects
Best Specialty Fertilizer: Carbon Phix
We at Lawn Phix helped create this lawn fertilizer. Manufactured and distributed by EffortLush (by Kelp4Less), Carbon Phix is the best alternative to Carbon X fertilizer. There are some things that Carbon X did have that Carbon Phix does not (like poultry manure) but otherwise, Carbon Phix checks all the boxes.
This granular fertilizer has an NPK ratio of 21-0-12. It contains 21% nitrogen (60% of which is slow-release) and 12% potassium (SOP). Also in the mix are secondary ingredients like 14% sulfur, 12% carbon, 6% iron, and 5% humic acid. Kelp4Less sources some of the best mined minerals in North America, and this bag of lawn fertilizer is packed with nutrients for lush green grass.
I use this as Round 3 for my clients in June as it provides plenty of nutrients to help feed the turf through the harsh summer months.
- Contains 60% slow-release nitrogen
- 12% potassium in the form of sulfate of potash (SOP)
- Contains organics, calcium, and sulfur
- Makes grass greener
- Inconsistent prill sizes
Best Non-Burning Fertilizer: Milorganite
Milorganite is one of the most popular and best slow-release fertilizers on the market. Used as a supplement in your lawn care program, Milorganite will result in greener grass and show a vast improvement to your lawn’s health.
The NPK ratio is 6-4-0 and 2.5% chelated iron. The major benefit to natural fertilizers like Milorganite is the organic matter which feeds and activates soil microbes. This is also safe to apply in the summertime and can provide up to 10 weeks of the slow-and-steady release of nutrients to feed your lawn.
You will need two 32 lbs. bags to cover 5,000 square feet to deliver 0.77 lbs of Nitrogen per 1,000 sq. ft.
For my customers that want to apply something, I tell them to use half rates of Milorganite in July.
- Contains 6% iron for extra greening
- Non-burning – can be applied in the summer
- PFAS (forever chemical)
- One bag covers just 2,500 sq. ft.
- The strong, distinct aroma
Best Liquid Fertilizer: CoRoN 18-3-6
This was by far the best liquid fertilizer I’ve used – particularly on my Poa Reptans putting green grass. I’ve tried other brands like Simple Lawn Solutions and Lawn Star, but I saw the best response with CoRoN 18-3-6. My recommendation is to apply half the recommended rate more frequently. This is essentially “spoon-feeding“.
Liquid fertilizers can be a nice alternative method of applying fertilizer to granular fertilizers for an established lawn. They can be applied with a backpack sprayer or even a hose-end sprayer. There are foliar qualities to these liquids – taken in the plant through the grass blades versus systemically through the roots – and show immediate response with a quick green-up.
This 2.5-gallon jug of liquid lawn fertilizer is applied at 22 ounces per 1,000 sq. ft. which yields in 14,500 sq. ft. of total coverage. But as previously mentioned, I recommend applying approximately 11 ounces per 1,000 sq. ft.
- Covers over 14,000 sq. ft.
- Contains chelated iron
- Will stain patios & vinyl fencing
How to Choose the Best Lawn Fertilizer for Your Grass
To begin your grass fertilizer selection process, perform a soil test. To conduct a simple soil test, you’ll need a soil sample. You can purchase a soil test kit or request that a local testing agency (i.e. university, garden centers, etc…) provide you with soil test results. A soil test shows the soil’s pH levels as well as its nutrient components like nitrogen, phosphorus, potassium, calcium, and iron. If your soil is low on these macronutrients and secondary nutrients, you’ll want to choose a lawn fertilizer that can provide whatever nutrients are lacking.
Feeding your lawn the nutrients it needs with the best lawn fertilizers will promote lush green grass growth, and a healthy lawn is its own best defense against lawn pests and grass weeds / broadleaf weeds. You might also want to choose a grass fertilizer with a weed preventer.
Types of Fertilizers
Grass Fertilizers are available as:
- Granular fertilizer
- Liquid fertilizer
- Organic Fertilizers
- Synthetic Fertilizers/chemical fertilizers
Let’s explore the advantages and disadvantages of each grass fertilizer type so you can choose the best lawn fertilizer for your grass.
Granular fertilizer products are slow-release fertilizers and tend to be less expensive than liquid fertilizers. Nutrients aren’t readily available for plants in a granular fertilizer or slow-release fertilizer, but they will last longer. These products often contain granules with different nutrients; liquid fertilizer, in contrast, contains the same formulation throughout the product. If you don’t want to apply lawn fertilizer to your grass multiple times, you may want to choose a granular fertilizer instead. You can apply this lawn fertilizer with a broadcast spreader.
You can combine liquid fertilizer and water to spray on your grass. Liquid lawn fertilizer contains nutrients that your grass can absorb immediately since no granules need to break down in the soil. This type of fertilizer is not a slow-release fertilizer, so it will usually require more applications to your grass. These grass fertilizers have a lower salt content, which is better for developing grass roots, and are easy to apply with your garden hose. Usually, you’ will want to apply fertilizer in liquid form at half the recommended rate.
Organic fertilizers, like granular fertilizers, usually take longer to break down, but they tend to provide grass with more micronutrients than chemical fertilizers that usually contain macronutrients like nitrogen, so they support your lawn’s health in a well-rounded fashion. An organic grass fertilizer is safe to use on lawns where children and pets are present, and these fertilizers help to amend the soil.
Synthetic or chemical fertilizers feature fast-acting formulas and offer very specific ratios of nutrients. Such ratios can’t be guaranteed in organic fertilizer for grass. Many have added nutrients designed to promote green grass.
Slow-release nitrogen fertilizer
Slow-release, or time-release, will provide lawn fertilization and feeding to your grass over an extended period of time. The prills in the slow-release fertilizer will contain a coating, encapsulating the nutrients which will provide a gradual, steady nutritional uptake. Some acronyms of such coatings and slow-release verbiage are:
Organic fertilizers are also generally slower release.
- Maximizes nutrient uptake by the plant
- Reduces the risk of burning or leeching
- Results take longer to notice
Fast-release nitrogen fertilizer
- Also called quick-release fertilizer.
- Generally urea nitrogen
- Good for fall time and ‘nitrogen blitz‘
- Quick green-up and fast visual results
- Results are short-lived and more product is needed, sooner
Standard Fertilizer NPK ratio
A lawn fertilizer’s NPK ratio is different across all brands and types. A starter for new grass will usually be a 2-3-1 or 1-1-1 ratio. Synthetic fertilizers
The NPK stands for:
- N = Nitrogen (top growth)
- P = Phosphorus (root growth)
- K = Potassium (all-around plant health)
Lawn Fertilizers FAQs
What are the best numbers for lawn fertilizer?
Your fertilizer’s NPK ratio should be 3-1-3 or 4-1-2. Remember that N (nitrogen) supports top grass growth), phosphorus supports grass root growth, and potassium supports all-around grass health
What month should I fertilize my lawn?
At a minimum, apply fertilizer 4 times a year. For cool-season lawns, you should fertilize your lawn in March, May, early August, and late September.
Should I add more fertilizer to grass during the growing season?
You can add more fertilizer to your grass when it is actively growing. While you can apply fertilizer during the growing season, the best time to fertilize your grass is in spring. Adding too much of even the best fertilizers can burn out your grass or fertile weeds, which is something you want to avoid.