As warm weather approaches, homeowners and landscapers turn their attention outward. Plans for pruning and seeding are enthusiastically hatched and we begin to daydream about walking through our lush, green lawns, barefoot, under a clear blue sky.
If cultivating a resilient, healthy lawn is new for you, it can seem daunting, potentially expensive, and not very eco-friendly.
While that may have been the case decades ago, these days you have far more eco-conscious choices with great value for money. At the top of this list are the best fertilizers for grass in summer, as this is the time of year when your lawn will need to most protection from heat stress and drought.
No need to waste time researching which one may be the best for your hardiness zone and grass type. Below, you’ll find the 8 best options that I’ve personally tested and yielded fantastic results from.
- Quick Summer Lawn Fertilizer Picks
- Summer Fertilizers for Grass
- Best Summer Lawn Fertilizers
- 1. Advanced Lawn Liquid Fertilizer 16-4-8
- 2. Scotts Turf Builder Lawn Food 30-0-4
- 3. Simple Lawn Solutions Extreme Grass Growth 6-18-0
- 4. Miracle-Gro Water Soluble Lawn Food 30-0-6
- 5. Southern Ag Chelated Liquid Iron
- 6. The Andersons PGF Complete 16-4-8
- 7. Milorganite Organic Nitrogen Fertilizer
- 8. Scotts Green Max Lawn Food 27-0-2
- Fertilizing Lawn In Summer
- Verdict: Best Grass Fertilizer for Summer
- FAQs Summer Lawn Fertilizer
Quick Summer Lawn Fertilizer Picks
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.
Best Liquid Concentrate
1. 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.
Best Granular Fertilizer
2. Scotts Turf Builder Lawn Food 30-0-4
High nitrogen, slow-release granules containing humic acid to support the release of soil nutrients and boost growth.
Best for New Seeding and Sod
3. 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.
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Summer Fertilizers for Grass
Lawns are heavy feeders, which means the soil in which they grow can get depleted of nutrients quickly, especially in the active growing season. That’s why using summer fertilizers that replenish the soil of nutrients is vital in supporting consistent growth and lawn health.
The macro nutrients in summer grass fertilizers offer a range of benefits for lawns. For example, nitrogen stimulates blade growth and ramps up chlorophyll cell production for vibrant color. Phosphorous focuses on healthy roots and the development of buds in flowering lawn types, such as clover.
Higher potassium is often recommended for use on warm season turf grass with a warm climate and increasingly hot summer temperatures. This element works to improve the circulation and retention of water especially in times of drought. It also helps to protect against diseases and pests.
Most grass varieties are hard wearing and can withstand much of what summer brings. But, even the most robust lawn is not invincible. In summer, all grass types require consistent access to nitrogen for efficient chlorophyll production and photosynthesis to maintain a lush, vibrant color.
According to the University of Utah, conducting a soil pH test is the best way to determine what supplementary nutrients your soil needs. That way, you can establish what is the right N-P-K ratio to support your particular grass type and regional climate as well as the specific macro nutrients that your soil may be lacking.
Understanding N-P-K Ratios
“N-P-K” is an acronym for the three macronutrients that create the base of all fertilizers, as they’re represented on the periodic table. These are nitrogen (N), phosphorous (P) and potassium (K).
How to read an NPK is far easier than it might sound. For example, a 16-4-8 N-P-K fertilizer contains 16% Nitrogen, 4% Phosphorus, and 8% Potassium.
Since lawns generally need more nitrogen than phosphorus and potassium, chances are the fertilizer you choose will be one with a higher first number.
The remaining ingredients used in fertilizers consist of essential micronutrients such as iron, copper, calcium, and magnesium and fillers that make for easy use and disbursement of nutrients.
Slow-Release Lawn Fertilizer
Slow-release fertilizers are great choices for a number of reasons. They’re time-saving because you only have to apply them once for several months of continuous feeding.
Another is that granules release nutrients at a rate that lawns respond well to, a rate similar to what plants receive in the wild.
This gradual conveyance of nutrients, according to the Michigan State University Extension, is considered more eco-friendly, with “low risk of burning the turf; more even, sustained grass growth (less mowing); and less leaching into ground and surface water.”
Some slow-release granule brands are either activated by increasing temperatures and moisture availability or helped along by soil microbes that convert nutrients into a more easily absorbed form.
Slow releasers come in both organic and synthetic formulas. But, it’s interesting to note that while synthetics come in both slow and fast-acting options, organics are all, naturally slow-releasing.
Lawn Fertilizer Spray
That’s not to say liquid fertilizers don’t have their benefits. They absolutely do! Diluting these yourself, as required, gives you more control over dosage potency.
You could use these at full dosage on your lawn, then dilute them even further for other nitrogen-loving plants, like evergreens.
Liquids are fast-acting, sending vital nutrients directly to the roots. This is really beneficial when you need to revive a tired-looking lawn quickly. Or when summer temperatures suddenly skyrocket and your lawn starts to brown.
When used as a foliar spray, liquids are fantastic at greening up patches in my lawn where my dogs like to hang out. The downside is the risk of potential, hazardous run-off and root burn.
Let’s take a closer look at how each liquid option actually works.
Water-soluble
Generally sold in powder or granule form, this product is usually more cost-efficient and easy to store. Typically formulated with a lower NPK ratio, this is the least common choice for large expanses of grass. Yet, has proven effective for small grassy areas.
Liquid Concentrate
Typically sold in bottles or jugs, concentrates require mixing with water and usually only need a small amount to be effective. Making these really economical options as both a fast-acting soil soak and foliar spray. However, these should never be applied with dilution. Severe root and blade burn will result.
Ready-to-use
Premixed options cut out the middle-man, entirely. No need to dilute them or otherwise prepare them for application. Just pour them into your hose attachment and you’re good to go. In exchange for this convenience, though, ready-to-use options may come at a slightly higher price point. But, in a pinch, they’re absolutely worth it.
Chelated Iron Supplement
An iron deficiency in your soil will be obvious, causing large areas of your lawn to suddenly yellow. Dense clay, excessive moisture, and naturally, oxidized (rusted) iron in your soil will be the biggest culprits.
Lawns require an easily absorbed form of iron in order for nitrogen, phosphorus and potassium to effectively do their jobs. If you’re seeing chronic yellowing in your lawn, chelated iron is the most beneficial form to alleviate this.
Avoiding Fertilizer Burn on Grass
An iron deficiency isn’t the only cause of a yellowing lawn. If this happens within a week of fertilizing, it may be the result of fertilizer burn.
An iron deficiency will cause faded blade color. But, too much nitrogen, while otherwise critical to a healthy lawn, will result in roots and blades dulling in color, then becoming brown and crisp. With no way to revive them.
Luckily, there are a few easy ways to prevent this. Using a slow-release fertilizer is arguably the easiest.
- Following the manufacturer’s dosage and application recommendations
- Apply when the grass is dry, followed by a deep watering to activate the fertilizer and prevent burn.
If you’re using a spreader or hose attachment, ensure that your route has little overlap. Duplicate passes will inevitably overload certain areas with fertilizer more than others. If your lawn has yellow streaks in it, this is most likely what has occurred.
Best Summer Lawn Fertilizers
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.
1. Advanced Lawn Liquid Fertilizer 16-4-8
Best Liquid Concentrate
- 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
- 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 ‘all-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.
3. Simple Lawn Solutions Extreme Grass Growth 6-18-0
Best for New Seeding and Sod
- 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 in this liquid concentrate is most suitable when establishing root growth is the primary concern. For example, when I am planting new seeds or sod, I use a phosphorus heavy fertilizer to help establish and develop a healthy root system.
This is also a great option if you have conducted a soil pH test and the results show a lack of phosphorous.
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.
I like that this product comes with a handy spray attachment meaning I don’t need to decant the solution into my own spray bottle or buy a new one. I can simply attach it to my garden hose and get on with the job.
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
- 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 as well as using it as a summer fertilizer to encourage new and thicker growth. I found that the enhanced new growth did a great job of crowding out an otherwise weedy lawn.
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 can be used on all grass types but is most suited to established lawns rather than applying it to 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.
- 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.
6. The Andersons PGF Complete 16-4-8
Best Coverage
- 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.
7. Milorganite Organic Nitrogen Fertilizer
Best Natural 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.
- 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 Fertilize
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 Liquid and Granular Fertilizers
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 Fertilize
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 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.
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.
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 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.