8 Best Fertilizers For Grass in Summer | Lawn Fertilizing

The summer months are rapidly approaching and if keeping up with the Joneses is your thing, it can be a lot easier to do so when they drive by and are envious of your luscious and vibrant front yard. 

At first, creating a beautiful lawn can be daunting especially when you know that one of the key criteria for healthy, green grass is using the right fertilizer and you need to make a selection from all the hundreds that are available.

With endless choices available on the market, choosing the right one can leave even the most confident rubbing their chin. Fortunately, with a little bit of explanation, it doesn’t have to be as hard as it seems. I have tested eight of the top fertilizers on the market; here’s what I found. 

Best Fertilizers For Grass In Summer

If you’re in a hurry, then here are my top recommendations for liquid concentrate and granule products. I have also included the best product for treating new sod.

Advanced Lawn Food Natural Liquid Fertilizer 16-4-8 

Best Liquid Concentrate

Advanced Lawn Food Natural Liquid Fertilizer 16-4-8 

Complete with a spray hose attachment, this pre-mixed formula offers fast-acting results and coverage of up to 3,200 sq. ft. Suitable for all grass types.

Scotts Turf Builder Lawn Food 30-0-4

Best Granular Fertilizer

Scotts Turf Builder Lawn Food 30-0-4

Scott’s high nitrogen (30-0-4) granules contain humic acid to support the release of soil nutrients to further boost growth.

Simple Lawn Solutions Extreme Grass Lawn Booster 6-18-0

Best for New Seeding and Sod

Simple Lawn Solutions Lawn Booster 6-18-0

Professional-grade high phosphate fertilizer (6-19-0). Perfect for new grass or when your lawn is worn and requires strong root growth.

Summer Fertilizers for Grass

Most varieties of established grass are hardwearing and can withstand much of what summer brings – droughts, heavy footfall, ball games, and even an unsharpened mower blade from time to time. 

The grass is not invincible, however. In the summer months, it needs nitrogen to maintain a lush vibrant color and to encourage new growth. It also needs phosphorus to ensure a sturdy and robust root structure.

A good quality summer fertilizer for grass will enable you to get the right balance of these two macronutrients so that your lawn looks healthy and keeps growing throughout the season.

Summer Fertilizer N-P-K Ratio

The N-P-K ratio is the amount of Nitrogen, Phosphorous, and Potassium, respectively, those fertilizer products contain. For example, if a fertilizer has a 3-4-5 N-P-K ratio, it contains 3% Nitrogen, 4% Phosphorus, and 5% Potassium. 

In simpler terms, a 100-pound bag with a 3-4-5 NPK ratio would contain 3 pounds of Nitrogen, 4 pounds of Phosphorus, and 5 pounds of Potassium. The remainder is made up of micronutrients such as iron, copper, and magnesium, plus fillers.

Plants require six primary ingredients to grow: carbon, hydrogen, oxygen, nitrogen, phosphorus, and potassium. The last three are macronutrients that can be found in soil. Although at times, these get depleted and need to be supplemented to create an optimum growth environment. 

For lawn care and when growing evergreens, nitrogen is an essential macronutrient that’s needed throughout the year. It’s used to stimulate leaf growth and create a more vibrant color. Almost all lawn fertilizers have a high Nitrogen content. 

Lawns need phosphorous to grow healthy roots primarily and in flowering trees and shrubs, it is needed to support the development of buds and flowers. 

In lawn care, phosphorous can be added to established lawns or new sod in Spring at the beginning of the growing season to encourage roots to become established.

Applying potassium to lawns in the Fall can help to protect your turf against adverse weather conditions such as frost, snow, and heavy rain. 

Slow-Release Lawn Fertilizer

This product works precisely how it sounds. If you want to minimize the amount of time you spend doing yard work, this might be a prime choice. In short, this type of fertilizer releases a constant amount of nutrients into the soil over time. 

Some slow-release products are organic, thus releasing nutrients as they decompose and break down naturally. 

Most commonly, these fertilizers are coated with a sulfur-based polymer or plastic resin that will release nutrients as the outdoor elements break down the artificial coating. 

Pound for pound, slow-release fertilizer is more expensive than faster-acting products. However, the infrequent application required of slow-release products generally makes the yearly bill about the same. 

Lawn Fertilizer Spray

Liquid fertilizer comes in three general forms: water-soluble, liquid concentrate, and ready to use, although all three forms involve a specific amount of powder or liquid per gallon of water. 

Liquid sprays feed plant growth in two ways, through the soil and the leaves directly. Absorption rates through leaves are much quicker than soil, generally yielding a speedier result with sprays. 

All varieties of liquid fertilizers are fast-acting. Applied with either a watering can or a simple hose attachment, nutrients are carried directly into the soil to the roots or over leaves and stems. 

The downside is the risk of run-off where the product is drawn away from areas where it provides benefit and instead, can leach into water sources and become a hazard.

Here is a quick breakdown of each.

Water-soluble

Generally sold in powder form, this product is cost-efficient and easy to store. Often sold for feeding house plants, it is the least common choice for lawn care. Thus, the variations of N-P-K ratios are more limited with this option. 

Liquid Concentrate

Typically sold in a bottle or jug, this product works water-soluble and only requires the user to mix a specific amount of concentrate with water. Apply it directly over the soil to benefit roots or use it as a foliar spray to be absorbed by leaves and stems for fast-acting results. 

Ready-to-use

A primary choice for beginners or the homeowner in a time crunch, this variation is generally sold with a hose attachment that releases pre-mixed and therefore an even spread of fertilizer. 

This product is available by numerous top brands and prevents you from purchasing additional equipment. It is also easy to store and quick to use. 

Chelated Iron Supplement

Plants with an iron deficiency will display different levels of discoloration ranging from dull yellow to brown. Soils like clay and water-saturated soil prevent iron from being available to plants. 

When iron reacts with oxygen and hydroxide, it is unavailable for plant use. To combat this, a chelate is used to inhibit iron oxidation, making it readily available to absorb and use by plants to produce healthy and vibrant foliage. 

Avoiding Fertilizer Burn on Grass

If grass displays yellow or brown patches after a fertilizer treatment, there is a good chance the lawn has been scorched by too much fertilizer product. 

This is usually easy to determine as the grass will appear damaged instead of just losing its vibrance. Luckily, there are a few easy ways to prevent this from happening. 

Using a slow-release fertilizer is arguably the easiest. Following the manufacturer’s instructions and administering an application when the grass is dry, followed by adequately watering the yard to activate the fertilizer will all help to prevent burn. 

If you’re using a spreader/granule combination, ensure that your route doesn’t have much overlap. Overlapping passes will inevitably overload or saturate certain areas with fertilizer more than others. If your lawn has yellow streaks every few feet, this is most likely what has occurred. 

Best Fertilizers For Grass in Summer Reviews

So after working my way through dozens of fertilization products, I have concluded my short list of the best fertilizer for use on lawns during summertime. My preference for summer treatment is by way of a hose-end spray and I like to apply it early morning when cloudy is forecast. This allows me to water it in and get quick results.

However, I also appreciate some of you guys prefer to broadcast granules, so I have included a number of granular products too that I have had great results with too. Just remember to water your lawn after fertilizing with granules.

Advanced Lawn Food Natural Liquid Fertilizer 16-4-8
  • Type: Liquid Concentrate
  • Application: Hose End Spray
  • Coverage: 3,200 sq.ft.
  • N-P-K Ratio: 16-4-8

Pros

  • Quick and easy to use
  • Fast-acting formula

Cons

  • Other options might provide more coverage

The Advanced Lawn Food Natural Liquid Fertilizer comes in at the top of my list as the best liquid concentrate fertilizer. When convenience and speed are a top priority, this one nails the brief because it is pre-mixed and the bottle features a hose attachment. 

You can use it year-round due to the balanced N-P-K ratio that supports every grass-growing phase. The high nitrogen count encourages growth, while the lesser phosphorus and potassium levels contribute to root development and temperature resistance.

I like the fast-acting nature of this product as I saw noticeable results within a few weeks. This fertilizer also has a seaweed and fish blend to provide additional nutrients to your soil. You can use it on any grass species.

How to Use

Attach the bottle to your garden hose via the twist screw end. Turn on the water to about 50% of the full pressure. Press the notch to release the fertilizer. Spray around the perimeter first and then row-by-row until you cover your lawn.

2. Scotts Turf Builder Lawn Food 30-0-4

Best Granular Fertilizer

Scotts Turf Builder Lawn Food 30-0-4
  • Type: Granules
  • Application: Broadcaster
  • Coverage: 5,000 sq.ft.
  • N-P-K Ratio: 32-0-4

Pros

  • Nitrogen-heavy to promote continuous growth and extra green grass
  • A formula that guarantees no scorching
  • Vast coverage at an affordable price

Cons

  • Requires a broadcaster

The Scotts Turf Builder Lawn Food is 32% nitrogen, so it facilitates the growth of bright green grass. The inclusion of potassium also helps to protect your grass from heat and drought as well. Since it does not contain phosphorus, you can use it in states that prohibit the use of this ingredient.

This granular fertilizer is a slow-release feed, meaning it releases nutrients gradually for about four to eight weeks. And, with Scotts ‘In one particle technology, you are guaranteed even coverage that results in more consistent feeding and color. 

I have the best results when I apply it once in June and once in August. As with all fertilizer products, it’s imperative to avoid over-fertilizing the grass, especially with granular lawn food. Most high-nitrogen fertilizers are prone to scorching grass blades and roots, however, this blend from Scotts offers a further guarantee of no burning.  

How to Use

Shut off the flow lever on the broadcaster. Fill the hopper with sufficient granules for your lawn size and choose the distribution rate number. 

Place the spreader three feet from the edge of your lawn. Squeeze the handle to dispense the fertilizer, first around the perimeter and then row

-by-row. Overlap the fertilizer application by 6-12 inches. Release the lever when you turn. Water the lawn when you finish.

Simple Lawn Solutions Extreme Grass Growth Lawn Booster 6-18-0
  • Type: Liquid Concentrate
  • Application: Hose End Spray
  • Coverage: 3,200 sq.ft.
  • N-P-K Ratio: 6-18-0

Pros

  • Easy to use
  • Promotes root growth

Cons

  • Lower nitrogen to reduce root scorching risk

The high phosphorus level makes this liquid concentrate most suitable for the new growth of roots. When you plant seeds or sod, the addition of phosphorus is needed to help establish and develop a healthy root system. 

This is also an option for over-fertilized lawns that can result from using high nitrogen fertilizer products. I recommend this to remedy the damage that can be caused.

Simple Lawn Solutions fertilizer supports all grass species. It contains humic acid to increase the release of nutrients from the soil to further boost growth and N-P-K absorption.

How to Use

Attach the bottle to your garden hose. Turn on the water to approximately 50% of the full pressure. Squeeze the button to release the fertilizer. First, spray around the perimeter. Then, apply the product row-by-row. You do not need to water your lawn when you finish.

4. Miracle-Gro Water Soluble Lawn Food 30-0-6

Best Water-Soluble Fertilizer

Best Fertilizers For Grass in Summer
  • Type: Water-soluble
  • Application: Hose End Spray
  • Coverage: 7,200 sq.ft.
  • N-P-K Ratio: 30-0-6

Pros

  • Large coverage area
  • Cost-effective
  • Easy to use

Cons

  • Hose-end sprayer not included
  • Requires frequent application

The Miracle-Gro Water Soluble Lawn Food is economical and effective. It is a fast-acting feed that you need to apply every 2-3 weeks during the growing season. You can apply it in the spring and summer to encourage new and thicker growth. This fertilizer works on all grass types.

Since it does not have phosphorus, you can use it in states that prohibit the use of this nutrient. However, you should avoid over-fertilizing your lawn. The high nitrogen content could scorch the blades or roots. 

This water-soluble option is most suited to established lawns rather than newly laid sod. It is also worth noting here that you will need to buy a separate hose-end sprayer.

How to Use

Fill a hose-end sprayer with the lawn food and connect the bottle to your garden hose. Turn on the water to around 50% of the full pressure. Press the button, switch, or notch to release the fertilizer. First, spray around the perimeter. Then, apply the product row-by-row.

Southern Ag Chelated Liquid Iron
  • Type: Liquid Concentrate
  • Application: Hose End Spray
  • Coverage: 1,000 sq.ft.
  • N-P-K Ratio: 5% soluble iron, 3.5% chelated iron, 3.4% combined sulfur

Pros

  • Spot-treatment
  • Easy to apply

Cons

  • Less versatile than a traditional fertilizer

If your lawn turns yellow, then the likely problem is an iron deficiency and that’s when you need a product such as Southern Ag Chelated Liquid iron to bring the greenness back. 

I use this fertilizer when I want to brighten my yard without promoting extra growth. It is also invaluable if your grass has been damaged from over-fertilizing with nitrogen.

The liquid iron works on all grass types, and you will notice results within a few days. The results last for 5-8 weeks before you need to reapply. You can apply a little more iron than the guide suggests but try to stick to the instructions for the first go-around before changing the dose.

How to Use

Add some liquid iron to a hose-end sprayer. Attach the sprayer to your garden hose. Turn on the water to around 50% of the full pressure. Press the button, switch, or notch to release the fertilizer. Start spraying around the perimeter before applying it row-by-row.

The Andersons PGF Complete 16-4-8
  • Type: Granules
  • Application: Broadcaster
  • Coverage: 10,000 sq.ft.
  • N-P-K Ratio: 16-4-8

Pros

  • Fast-acting
  • Large coverage area

Cons

  • One of the pricier options
  • Needs a broadcaster

I was impressed by the expansive coverage that this fertilizer provides. This 40-pound bag of granular fertilizer has super fine particles to deliver twice the amount of granules per square foot. I noticed the difference in the uniformity of the distribution.

The Andersons Professional PGF fertilizer provides slow-release nutrients that provide eight weeks of fertilizing. You will notice a difference within 6-14 days.

How to Use

Shut off the flow lever on the broadcaster. Fill the hopper with enough granules for your lawn and set the distribution rate number. Place the spreader three feet from your lawn’s edge. Press the handle to dispense the fertilizer around the perimeter first and then row-by-row. Overlap the fertilizer by 6-12 inches. Release the lever as you turn. Water the lawn to finish.

Milorganite Organic Nitrogen Fertilizer
  • Type: Granules
  • Application: Broadcaster
  • Coverage: 2,500 sq.ft.
  • N-P-K Ratio: 6-4-0

Pros

  • Requires less frequent application
  • Made from organic materials
  • Non-burning

Cons

  • Small coverage area
  • Requires a broadcaster

This organic, slow-release, non-burning fertilizer works well in areas that do not get frequent rainfall or have inactive irrigation. It does not contain salts that could further dry out the lawn. The granules last up to ten weeks before requiring reapplication. 

While this fertilizer has less nitrogen, you can use it if your soil has balanced nitrogen levels or if you are concerned about scorching your lawn. It has no potassium in it, which you do not need during the summer as it protects against cold temperatures.

How to Use

Shut off the flow lever on the spreader. Fill the hopper with enough granules and select the distribution rate. Set the broadcaster three feet from your lawn’s edge. Squeeze the handle to release the fertilizer around the perimeter of your lawn. Hit the rest of the grass by spreading it row-by-row. Overlap the fertilizer 6-12 inches. Release the handle as you turn. Water the lawn to finish.

Scotts Green Max Lawn Food 27-0-2
  • Type: Granules
  • Application: Broadcaster
  • Coverage: 5,000 sq.ft. 
  • N-P-K Ratio: 27-0-2

Pros

  • Easy to use
  • Non-staining

Cons

  • Requires a broadcaster

The Scotts Green Max Lawn Food does not stain your driveway. I love that I do not need to power wash the concrete after a long day of yard work. You can also step on your lawn after applying the product, which helps when you have other things to accomplish that day.

Within three days, this fertilizer began working. The non-staining formula features 5.17% iron, 27% nitrogen, and no phosphorus. It’s a great choice for states that ban the use of phosphorus.

How to Use

Shut off the flow lever. Fill the hopper with granules and choose the distribution rate. Put the broadcaster three feet from the edge of your lawn. Squeeze the handle to distribute the fertilizer around the perimeter. 

Fertilize in a row-by-row manner. Overlap the fertilizer by 6-12 inches and release the handle as you turn. Water the lawn when you finish.

Fertilizing Lawn In Summer

Now that I have provided my top list of summer fertilizers, let’s break down how and when to use them. Timing is everything when it comes to lawn care. Applications too soon don’t yield desired results, and applications too late can be detrimental to lawn health.

When to Apply Fertilizer to Lawn in Summer

Start fertilizing in spring after the last frost. Use a nitrogen-rich and high phosphorus fertilizer to kickstart growth both above the surface and below.

In summer, apply a high nitrogen feed to fuel energy into thick, sturdy blade production. Adding iron here as well as a high nitrogen fertilizer will enhance the vibrant greenness.

Apply fertilizer as recommended by the manufacturer until temperatures in your region rise above 80 degrees Fahrenheit. Avoid fertilizing when temperatures exceed 80 degrees Fahrenheit as this can dramatically increase the risk of burning your lawn. 

During these barmy conditions, and even if your lawn is looking lackluster, avoid the urge to fertilize; it doesn’t take much to over-fertilize. This period is generally when most grasses are actively growing, although some types of grass go dormant during the brutal summer heat.  

If you choose to fertilize in the fall, choose a product with added potassium to encourage protection against pests and diseases and enhance winter hardiness. Avoid high nitrogen as this can trigger new growth that could be detrimental if frost then occurs. 

Before applying fertilizer, you’ll need to establish whether you have cool or warm-season grass, with cool-season (rye, fescue, bluegrass) growing primarily in cooler temperatures and warm (St. Augustine, Bermuda, Zoysia) seasons getting most growth in hotter conditions. You should then select a fertilizer product that is specifically designed for your grass type.

How to Apply Lawn Fertilizer in Summer

The “how to” of applying fertilizer unequivocally begins with research and understanding which product you have chosen and how that specific product works. However, there are a few general and universal practices to follow. First, determine what equipment you will need: a broadcaster, hose-end-sprayer, mixing container, etc. 

You should aim to apply fertilizer to wet grass; an application on dry grass can increase the risk of lawn burn. 

Beware of ‘overlapping’ as you fertilize. This can cause excessive amounts of product where the two passes meet and chemically burn the grass. I have found that this most commonly occurs when using a broadcaster; however, I would still recommend paying attention to overlapping spray patterns when using a hose-end-sprayer. 

I have made it standard practice to spray down treated grass to ensure there is no buildup of fertilizer causing damage and to help saturate the soil with nutrients. 

I would recommend staying off the lawn for at least 24 hours after an application and waiting at least 48 hours before running a mower over the grass. 

The type of product you choose comes down to personal preference. A sprayer will distribute an even stream of fertilizer as you water the grass. 

Slow-release variants are great, requiring fewer applications and thus, saving time. I think these are great options for those in a time crunch and novice lawn enthusiasts alike. 

How Often to Apply Fertilizer

I will always recommend referring to a provided user manual or manufacturer recommendations when deciding how often to apply a fertilizer treatment. Understanding what product you have purchased is crucial. A slow-release formula does not need to be applied as often as a fast-acting treatment. 

You should aim for temperature windows that fit your lawn’s prime growing conditions, totaling 5-6 applications a year. Organic fertilizer can be applied a little more liberally as it tends not to burn grass as easily as its synthetic counterpart. Organics are also drought-resistant and will not necessarily be harmful to your lawn in dry conditions. 

Verdict: Best Grass Fertilizer for Summer

My personal favorite and the go-to choice for fertilizing my yard are Advanced Lawn Food Natural Liquid Fertilizer 16-4-8. The generous 3,200 square foot coverage I suitable for moderate lawns for use throughout the summer months. 

The power-packed, natural, and fast-acting blend of macronutrients keeps my grass rich and vibrant for longer than other brands I have used. I find that it keeps my soil healthy and my lawn free from scorching even into the brutally hot and dry months. 

Advanced Lawn Food Natural Liquid Fertilizer 16-4-8 

Best Liquid Concentrate

Advanced Lawn Liquid Fertilizer 16-4-8 

Complete with a spray hose attachment, this pre-mixed formula offers fast-acting results and coverage of up to 3,200 sq. ft. Suitable for all grass types.

Scotts Turf Builder Lawn Food 30-0-4

Best Granular Fertilizer

Scotts Turf Builder Lawn Food 30-0-4

Scott’s high nitrogen (30-0-4) granules contain humic acid to support the release of soil nutrients to further boost growth.

Simple Lawn Solutions Extreme Grass Lawn Booster 6-18-0

Simple Lawn Solutions Lawn Booster 6-18-0

Professional-grade high phosphate fertilizer (6-19-0). Perfect for new grass or when your lawn is worn and requires strong root growth.

If it’s a granular feed you prefer, then choose Scotts Turf Builder Lawn Food 30-0-4. The mix of high nitrogen combined with humic acid will improve overall growth and color when used during summer applications. Or, if it’s freshly laid sod that needs some attention or a re-seeding project you undertaking during the growing season, choose Simple Lawn Solutions Extreme Grass Lawn Booster 6-18-0. The addition of phosphorous here will help establish a strong and healthy root system.

FAQs Summer Lawn Fertilizer