13 Best Liquid Lawn Fertilizer Concentrates & How To Use Them


Fertilizing regularly is part of essential lawn care, especially if your soil and grass are lacking nutrients. From granular to liquid fertilizers, there is a large range of fertilizers on the market and it can be difficult to find the right one for your lawn.

Liquid lawn fertilizer concentrates often yield immediate results, and they are a great option for very cost-effective and long-term care for your lawn. Most liquid fertilizers contain iron and other nutrients that support your grass throughout the year.

The detailed guide in this article will help you choose the right liquid lawn fertilizer for your lawn care. We a take a look at a number of liquid lawn fertilizer concentrates and find out which one works best for certain grass types, and how to use them.

13 Best Liquid Lawn Fertilizer Concentrates

Not sure what liquid lawn fertilizer to choose? Here are our 13 best liquid lawn fertilizer concentrates judged by value for money, performance, fertilizer compounds and customer satisfaction. 

Scotts Liquid Turf Builder Lawn Food 29-0-3

Scotts Liquid Turf Builder Lawn Fertilizer for All Grass Types, Feeds and Waters Lawn at Same Time, 32 fl. oz.

Scotts is one of the best known lawn care brands on the market. The Scotts Liquid Turf Lawn Food comes with a 2 in 1 formula that can easily be spread with a hose pipe attachment. Just connect your hose to the bottle, activate the trigger and you basically water your lawn together with the fertilizer. With its 29-0-3 nutrient ratio, this high nitrogen fertilizer is designed to be used throughout the season. It even contains a so-called greening agent which promises to give your lawn a lush green look.

The majority of liquid fertilizers come in a handy spray bottle that you need to connect to a hose pipe attachment. This approach is very effective in spreading the fertilizer evenly across the grass, and it saves you a lot of time. The bottle of the Scotts Liquid Turf Builder has a simple on/off lever at the top so that you can actively control the water flow. 

With the 32 oz. bottle you can cover up to 2,000 square feet of lawn. However, this does depend on the pressure of your hose. The faster the water flow, the quicker the fertilizer will be drawn out. 

How to use Scotts Liquid Turf Builder Lawn Food: Simply screw your water hose attachment into the back of the bottle, and when you are ready use your thumb to flip over the lever to activate the trigger sprayer. Cover the lawn area you want to fertilize. When you are done, turn the lever into the off position, turn off the water and unscrew the bottle from the hose. This way you can use the bottle several times throughout the season.  


  • Handy spray bottle – Just screw your hose into the bottle and start spraying
  • For use throughout the season
  • Contains a greening agent for fresh looking, green lawn
  • Suitable for all grass types
  • No risk of burning or scorching


  • Spray bottle is not as easy to handle with one hand as some other liquid lawn fertilizers

What customers say: Customers of the  Scotts Liquid Turf Lawn Food have noticed a quick improvement of their lawn, from tired-looking grass to a bright green. They also like the spray bottle which means you don’t need a spreader.

Scotts Liquid Turf Builder Lawn Fertilizer for All Grass Types, Feeds and Waters Lawn at Same Time, 32 fl. oz.
  • Scotts Liquid Turf Builder Lawn Food contains the essential nutrients and feeding power lawns need for great results
  • This 2-in-1 liquid fertilizer makes it easy to feed and water your grass at the same time
  • Apply this grass fertilizer to actively growing turf
  • This lawn care product can be applied to any grass type
  • One 32 fl. oz. bottle of Scotts Liquid Turf Builder Lawn Food covers 2,000 sq. ft.

Simple Lawn Solutions 3-18-18 Liquid Lawn Fertilizer

Ultimate 3-18-18 NPK- Lawn Food Quality Liquid Fertilizer- Easy to Use Concentrated Spray- Any Grass Type- Summer & Fall Nutrients- Simple Lawn Solutions - Turf Hardiness & Root Vigor (32 Ounce)

A lawn fertilizer formulated by family-owned company Simple Lawn Solutions, this liquid lawn fertilizer is particularly good for lawns that need potassium and phosphorus. The 3-18-18 nutrient ratio is made with organic ingredients, encouraging grass roots to grow strong and healthy without chemicals. This natural lawn fertilizer doesn’t burn or damage your lawn.

How to apply Simple Lawn Solutions Liquid Lawn Fertilizer: Same as all the other fertilizers, the fertilizer products by Simple Lawn Solutions are in a spray bottle that allows you to spread the fertilizer with as little time and effort as needed.


  • Can be used on all grass types
  • Quickly turns tired grass into a lush, green lawn


  • Spray bottle top prone to breakage

What customers say: Users of the Simple Lawn Solutions Liquid Lawn Fertilizer found the spray bottle very unreliable and easy to break. They were particularly impressed that it supports the growth of strong roots with a bright green top growth.

Ultimate 3-18-18 NPK- Lawn Food Quality Liquid Fertilizer- Easy to Use Concentrated Spray- Any Grass Type- Summer & Fall Nutrients- Simple Lawn Solutions - Turf Hardiness & Root Vigor (32 Ounce)
  • High Phosphorus, High Potassium Lawn Food: If your lawn is showing symptoms of a Phosphorus and Potassium deficiency or if you want to maintain lawn health then this is the correct fertilizer for you!
  • Made With High Quality Feed Grade Ingredients: Nourish your lawn to its top potential with quality liquid lawn Nutrients.
  • Easy To Use: Designed to be easily applied. This high Phosphorus & Potassium Lawn Food gives your lawn the nutrients it needs for strong root development, vigor, and strength.
  • Can Be Used on All Grass Types: Including Bermuda, St. Augustine, Zoysia, Buffalo, Centipede, Palmetto & Bluegrass Lawns.
  • Easy to Use: Our 3-18-18 Lawn Fertilizer Food comes with a ready-to-use hose end sprayer that applies the perfect ratio of product for lawn applications. Covers up to 3,200 square feet, when using the attached sprayer.

Scotts Liquid Turf Builder Ready To Spray Fertilizer

Scotts Liquid Turf Builder with Plus 2 Weed Control, Liquid Weed Killer and Fertilizer, 32 fl. oz.

Just like its standard lawn food product, Scotts weed and feed comes ready with a hose-end attachment that’s easy to use. You don’t need to mix it with water, so no time wasting. Just get out and spray. 

Scotts liquid fertilizer is safe for all grass types, and as you just connect the spray bottle to your hose pipe, you also water your lawn at the same time. The bottle lasts for several applications throughout the season. 

This liquid weed control and fertilizer directly works on the grass root and stimulates new growth. Scotts liquid turf builder formula is a great choice for newly planted lawns with either sod or seed. Whether you use it on newly planted grass for growth or to established lawns, this liquid fertilizer gives all types of grass a nutrient boost during the growing season. 

While Scotts liquid fertilizer covers only 600 square feet, it produced much stronger grass than granular fertilizer. So we would definitely recommend this product for smaller lawns, and newly planted grass areas.

How to apply Scotts Liquid Turf Builder Ready To Spray Fertilizer: Attach your garden hose to the top of the spray bottle, turn the level into the on position and turn on your water. You can then evenly distribute the fertilizer by simply spraying the water across the lawn.

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  • Weed killer and fertilizer in one
  • Sprray bottle for easy and even application
  • Ideal for freshly sown grass


  • Small bottle with little coverage
  • May take longer to see greener top growth

What customers say: Users of the Scotts weed and feed were pleased with the results of greener and thicker grass, although it didn’t act as quickly as expected. They liked the spray bottle to achieve an even spread without burning the grass.

Scotts Liquid Turf Builder with Plus 2 Weed Control, Liquid Weed Killer and Fertilizer, 32 fl. oz.
  • Scotts Liquid Turf Builder with Plus 2 Weed Control kills listed weeds, all while giving your lawn a quick boost of nitrogen
  • Liquid weed killer plus fertilizer controls dandelion, clover, ground ivy, henbit, chickweed, plantain, poison ivy, and other broadleaf weeds as listed
  • Apply this ready-to-spray when weeds are actively growing
  • This lawn care product is for use on Bluegrass, Fescue, Ryegrass, Bahiagrass, Common Bermudagrass, Centipedegrass, and Zoysiagrass
  • Simply connect Scotts Liquid Turf Builder with Plus 2 Weed Control to a garden hose, turn on water, and spray

Southern Ag Chelated Liquid Iron For Lawns

Southern Ag Chelated Liquid Iron, 16 OZ

The bottle of this liquid lawn fertilizer from Southern AG might not look like much but the iron-rich formula brings tired lawns back to life. Although you do have to be careful when you handle it as it can stain hands and other things you get in touch with, but it turns grass a bright green color. This liquid iron feed is so good that you can even use it on vegetables, flowers and shrubs.

How to apply: Unfortunately this doesn’t come in a spray bottle so you have to mix this liquid iron for lawns with water. Then apply it as a drenching spray on the lawn. 


  • Suitable for all types of lawn, as well as vegetables, shrubs and plants
  • Quick results showing healthy, green grass
  • Easy application (once you mixed the liquid iron with water)


  • Be careful when handling, it can stain hands and concrete

What customers say: Customers recommended wearing gloves before applying this liquid iron as it easily stains your hands, and the smell can be very persistent. Most users tried the liquid feed on their trees and plants first which worked well. 

Southern Ag Chelated Liquid Iron, 16 OZ
  • Size: 16 OZ
  • Corrects Iron deficiency in flowers, vegetables, shrubs and trees.
  • Use in lawns for a deep, rich green color.
  • APPLICATION: Mix with water. Apply as a drenching spray.
  • For large quantity discount consideration or to request a mixed multi-pack, please message us.

Ferti-Lome Liquid Iron Lawn Fertilizer

Fertilome (10625) Chelated Liquid Iron and Other Micronutrients (16 oz)

This liquid fertilizer tackles iron deficiencies in lawns, houseplants, trees, shrubs, vegetables and flowers. However, this fertilizer contains a significant amount of iron and it’s not a full fertilizer on its own, so you should use it only in conjunction with a nitrogen lawn fertilizer to ensure your grass and other plants can absorb it. It’s effectively a special iron formula feed in addition to your normal fertilizer.

We would recommend using this fertilizer spray throughout the season. Just apply it every 8 weeks with your main fertilizer.

How to use Ferti-Lome Liquid Iron Lawn Fertilizer: Mix with water and pour into a spray bottle. Then spray evenly across your lawn.


  • A great iron-based formula feed in addition to a nitrogen-based lawn fertilizer
  • Good value for money liquid iron fertilizer
  • Also safe to use with indoor plants
  • Doesn’t stain


  • Should not be used on its own but in combination with a nitrogen lawn fertilizer

What customers say: Customers of the Ferti-Lome liquid iron lawn feed noticed quick results with grass turning bright green. Users also noticed a lingering smell after applying the fertilizer but it disappeared after two hours.

Fertilome (10625) Chelated Liquid Iron and Other Micronutrients (16 oz)
  • Quick, economical and easy correction of iron deficiency (yellowing of foliage) in your plants.
  • Nutritional spray adds other key micronutrients to your shrubs, lawns, tress, flowers & vegetables.
  • Concentrate readily mixes with water. Should not be substituted for fertilizer.
  • Apply 2 to 10 teaspoons per gallon depending on height of plant. See label for instruction.
  • Apply a thorough foliage spray to both sides of leaves. Mix 1 tablespoon per gallon of water.

Advanced 16-4-8 Liquid Lawn Fertilizer Spring & Summer

Advanced 16-4-8 Balanced NPK - Lawn Food Quality Liquid Fertilizer - Spring & Summer Concentrated Spray - Any Grass Type - Simple Lawn Solutions (32 Ounce)

Another formula from Simple Lawn Solutions, this quick-release liquid fertilizer contains seaweed and fish, as well as all the important nutrients for your lawn, including nitrogen. The Advanced fertilizer formula is one of the most popular fertilizers on the market. 

The 32-ounce bottle can cover up to 3,200 square feet to feed your lawn, and it’s suitable for all grass types. However, as this liquid fertilizer doesn’t stay in the soil for too long, you need to go through a  few applications throughout the growing season to see noticeably greener grass. It’s important that you keep your lawn well-watered so the nutrients can be absorbed by the grass roots.

How to apply Advanced Liquid Lawn Fertilizer: The ready-to-spray bottle makes it easier to apply this fertilizer evenly across your lawn. You just need to connect it to a hose pipe and spray, with applications in spring and summer. 


  • Works for all grass types
  • Can also be applied during dry weather (with sufficient watering)
  • Quick results with rich, green grass


  • Sprayer bottle not reliable

What customers say: Customers of the Simple Lawn Solutions advanced liquid fertilizer were impressed with the ‘overnight’ greener grass. They loved how easy it is to connect the spraying bottle to their garden hose and apply the fertilizer quickly.

Advanced 16-4-8 Balanced NPK - Lawn Food Quality Liquid Fertilizer - Spring & Summer Concentrated Spray - Any Grass Type - Simple Lawn Solutions (32 Ounce)
  • Complete NPK Lawn Food: 16-4-8 is the perfect blend of key macronutrients. This lawn liquid food turf fertilizer also contains Seaweed & Fish.
  • Contains High Quality Feed Grade Ingredients: Nourish your lawn with pure liquid Nutrients in a ready to use sprayer
  • Easy To Use: Designed to be easily applied. This complete Nitrogen, Phosphate and Potash formula gives your grass greening & growth while providing nutrients for lush lawns
  • All Grass types: Including Bermuda, St. Augustine, Zoysia, Buffalo, Centipede, Florida Palmetto, Bahia, Fescue, Ryegrass & Kentucky Bluegrass
  • Produced In The United States: 16-4-8 is manufactured in the United States of America, by a family owned business with 25 years of former experience in the commercial professional turf industry.

Marphyl Organic Liquid Soil Enhancer

MARPHYL Organic Liquid Hydroponics Fertilizer - Liquid Plant Food - All-Purpose, Nutrient-Rich Lawn Fertilizer & Soil Enhancer for House Plants, Flowers, Vegetables Succulents Bamboo

The liquid soil enhancer from Marphyl is 100% natural containing all the nutrients, vitamins and minerals your lawn needs. Whether in greenhouses, indoors or outdoors, this organic feed can also be used for vegetables, trees, plants and flowers. The organic formula boosts tired grass turning it into lush green by regularly providing nutrients to the soil.

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Marphyl suggests an application every two weeks which can be quite time consuming when you have a big lawn, so we would recommend this product for smaller lawns and grass areas.

How to apply Marphyl Organic Liquid Fertilizer: This liquid feed doesn’t come in a spray bottle so you need to mix it in a bucket with water.


  • Natural and eco-friendly lawn fertilizer
  • Suitable for lawns, trees, houseplants, shrubs and vegetables
  • Good value for money


  • No spray bottle
  • Needs to be mixed with water

What customers say: Customers of the Marphyl liquid soil enhancer loved that this fertilizer is so versatile. It works with houseplants as well as trees and lawns. They really liked that it’s an organic fertilizer which is friendly to the environment and wildlife.

MARPHYL Organic Liquid Hydroponics Fertilizer - Liquid Plant Food - All-Purpose, Nutrient-Rich Lawn Fertilizer & Soil Enhancer for House Plants, Flowers, Vegetables Succulents Bamboo
  • Superior Indoor Plant Fertilizer - MARPHYL Marine Phytoplankton is ideal as an outdoor and indoor plant fertilizer. It's an excellent vegetable fertilizer, houseplant fertilizer, and lawn fertilizer. It's great for your garden, greenhouse, and hydroponics. Enjoy gorgeous, colorful blooms with this exceptional flower food. Enhance soil quality and watch your trees, shrubs, vines, grass, plants, flowers, and vegetables thrive.
  • Natural Indoor Plant Food - Marine Phytoplankton are Microalgae full of nutrients, vitamins, and minerals. It's so much more than your average liquid plant fertilizer. MARPHYL's fertilizer for indoor plants and outdoor plants, grasses, trees, flowers and more, provides an astounding array of nutritional elements. Packed with vitamins, minerals, essential fatty acids, DHA, EPA, amino acids, chlorophyll, and a vast spectrum of phytochemicals, so your lawn, garden, and greenhouses will flourish
  • Organic & Sustainable - Our Liquid Marine Phytoplankton Soil Enhancer is an organic, all purpose plant food that is harvested 100% naturally. It's vegan, non-toxic, non-GMO & sustainably made with no preservatives making it safe for vegetable gardening, ground water, and pets. It replenishes your soil on a regular basis to ensure the continued growth and beauty of your vegetation. Our organic plant fertilizer will meet your every need and provide a safe environment for all gardening.
  • Miraculous & Beneficial - Found in oceans across the world, marine phytoplankton are micro algae that infuse your plants, trees, grasses, and more with everything they need for health and longevity. High in potassium, nitrogen, and phosphorus as well as calcium and magnesium for lush foliage. Your lawn & garden will be the envy of the neighborhood, and your indoor plants will brighten your home.
  • Easy to Use Water Soluble Fertilizer - Simply mix a 1:20 ratio of our liquid plant fertilizer with water. Once in the water, stir, and then pour onto the plants. Perfect for use in small and large sprayers. Recommended use is every two weeks. You'll see the difference after just one application!

FoxFarm Grow Big Soil Liquid Concentrate Fertilizer

FoxFarm Grow Big Gallon (4/Cs)

The FoxFarm liquid concentrate fertilizer is a blend of all essential nutrients your lawn and other garden plants need. The mix of nitrogen, phosphorus and potassium formula is designed to work for grass, roses, herbs, fruit, veggies and flowers. 

How to apply FoxFarm Liquid Concentrate Fertilizer: This liquid fertilizer needs to be mixed in water. Just add a few tablespoons into a bucket of water, and apply to your lawn with a garden sprayer.


  • Very cost-effective
  • Helps tired grass to look bright and green
  • Also suitable for vegetable and plant growth


  • Not organic

What customers say: Customers of FoxFarm’s liquid fertilizer concentrate are very pleased with how it helped vegetables and grass grow. Although it states organic-based, this fertilizer is not organic like some other brands that are based on a seaweed or corn formula.

FoxFarm Grow Big Gallon (4/Cs)
  • Get the garden growing with Grow Big , a fast-acting, liquid concentrate fertilizer for lush, vegetative, compact growth
  • Fortified with earthworm castings, Norwegian kelp and a super-concentrated micronutrient package, this special brew encourages a strong compact branching structure that supports more abundant buds and blooms

Miracle-Gro Water Soluble Lawn Food

Miracle-Gro® Water Soluble Lawn Food, 5 lb.

While the Miracle-Gro lawn food is granular, you need to dissolve it in water and then spray it across your lawn while watering. With applications every 3 weeks throughout the season you can help your grass grow stronger and greener. This Miracle-Gro formula is designed for turfgrass that needs a high nitrogen and iron level but it’s safe to use for all grasses. 

How to apply the Miracle-Gro lawn food: Simply mix 1 tablespoon of the fertilizer with every gallon of water and then apply with a watering can (or with Miracle-Gro garden feeder) every 2 to 3 weeks on your grass 


  • Greener grass within a week
  • Can feed up to 7,200 square feet of lawn
  • Can be used on all types of lawns


  • Needs to be dissolved in water and requires either a watering can or the Miracle-Gro garden feeder

What customers say: Customers also noticed that you should use a small dose of this fertilizer first, and measure carefully. They really liked that their grass was noticeably greener in a very short space of time.

Miracle-Gro® Water Soluble Lawn Food, 5 lb.
  • Instantly feeds all grass types
  • Encourages a soft green carpet of grass that will be the pride of the neighborhood
  • Feeds up to 7,200 sq. ft.
  • The fast way to a thick, green lawn
  • For use with the Miracle-Gro Garden Feeder

Simple Grow Solutions Natural Lawn & Garden Concentrated Fertilizer

Organic Super Seaweed Humic Acid Blend- Liquid Sea Kelp for Grass and Plants - Soil Hume - Simple Grow Solutions- Natural Lawn & Garden Concentrate- Use with Fertilizer Program (32 Ounce)

Well known in the markets for commercial agricultural, athletic turf, and golf course fertilizers, Simple Grow Solutions also wanted to offer their products to the general public, and this concentrated, affordable fertilizer is the result. Thie organic lawn and garden fertilizer is fully organic, based on a formula with humic acid and seaweed (harvested in the North Atlantic). This fertilizer also contains soil hume that helps your grass to retain soil nutrients releasing them over time.

It’s suitable for all grass types, including St. Augustine, Bermuda, Centipede, Kentucky Bluegrass, Ryegrass and many more. You can also apply it for a healthy crop and bloom on tomato plants, citrus trees and other vegetable plants.

How to apply Simple Grow Solutions Concentrated Fertilizer: You can apply this fertilizer in two ways. If you use a hose for application, then 10 ounces of fertilizer will cover up to 1,000 square feet. If you mix 3 ounces of the concentrate with one gallon water and apply it with a garden sprayer, you can cover 1,000 square feet with a gallon.  


  • A fertilizer trusted by farmers and agricultural professionals
  • Healthy lawn quickly
  • Can also be used for seeding, overseeding and new sod


  • Needs proper stirring as it can clog up sprayers

What customers say: Customers of the Simple Grow Solutions fertilizer concentrate noticed their lawns turning greener almost overnight. They liked that it’s organic and easy to use.

Organic Super Seaweed Humic Acid Blend- Liquid Sea Kelp for Grass and Plants - Soil Hume - Simple Grow Solutions- Natural Lawn & Garden Concentrate- Use with Fertilizer Program (32 Ounce)
  • Blended with 4% Seaweed: Liquid Sea Kelp Concentrate blended with Ascophyllum Nodosum Seaweed harvested in the Icy North Atlantic
  • Blended with 4.5% Humic Acid: Soil Hume is a Highly Concentrated form of Liquefied Carbon Derived from the Highest Quality Humate Source, Leonardite. Leonardite is Considered by many to be the Highest Quality form of Humic Acid
  • Versatile Formula for Lawn and Garden: Soil Hume Can help increase the Transfer of Nutrients and Help your Lawn, Garden and Plants Uptake Nutrients more Efficiently
  • Use Alongside Lawn Food Fertilizer Program. Can be used on all grass types including Bermuda, St. Augustine, Zoysia, Buffalo, Centipede, Florida Palmetto, Bahia, Fescue, Ryegrass & Kentucky Bluegrass
  • Application Rates for Garden: Use on Indoor Plants, Flowers, Roses, Tomato Plants, Vegetables, Fruit, Citrus, Garden Landscape, Hardy trees, Seeding, Over seeding and New sod. Use Alongside Plant Food Fertilizer Program

Organic Kelp Fertilizer

Organic Kelp Fertilizer by GS Plant Foods - Omri Certified (1 Quart) - Kelp Fertilizer for Gardens, Lawns & Soil

Seaweed, also known as kelp, is one of nature’s organic plant foods. The fertilizer from GS Plant Foods is made with a special blend of kelp that helps to stimulate natural root growth of your lawn as well as better mineral update. The liquid kelp fertilizer can be used on any type of soil and grass without the risk of burning.

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Also used in commercial agriculture, this fertilizer acts as an organic soil conditioner improving soil conditions for each growth stage of the grass. In our test, we found that applying the feed every 4 to 7 days is very time consuming but well worth the effort when you want to bring a lawn to a healthy state. As this organic concentrate contains no harmful chemicals, you can also use it on other shrubs, trees and plants in your garden.

How to use organic kelp fertilizer: Shake well and then dilute one ounce of the kelp fertilizer in one ounce of water. Then apply the liquid with a garden sprayer evenly across the lawn.


  • Can be used on lawns, vegetable plants and trees as well as aero gardens
  • Organic and friendly to the environment
  • Made with organic material


  • Strong odor
  • Needs to be used in conjunction with another fertilizer 
  • Requires application every 4 to 7 days

What customers say: Customers of organic kelp fertilizer noticed the strong smell when handling the product but they were very pleased with the strong growth of their grass.

Organic Kelp Fertilizer by GS Plant Foods - Omri Certified (1 Quart) - Kelp Fertilizer for Gardens, Lawns & Soil
  • OMRI ORGANIC LISTED SEAWEED & KELP FERTILIZER: Liquid Kelp is a natural plant food that provides a range of benefits for plant health and nutrition. OMRI listed for organic use, GS Plant Foods Liquid Seaweed Fertilizer is a completely natural, seaweed extract fertilizer for plants. Our liquid seaweed will optimize soil conditions for greater root mass and improve nutrient uptake. It can be applied without concern for harmful chemicals or nutrient loss to the environment.
  • ONE OF NATURE’S ‘MIRACLE’ PLANT FOODS: Made from the finest seaweed plant Ascophyllum Nodosum, this is one of nature’s miracle plant foods. Our seaweed extract improves your plant’s tolerance to excessive heat, wind, drought conditions and more. It increases and stabilizes chlorophyll in plants, which results in darker green leaves and increased sugar content in plants.
  • IMPROVES OVERALL PLANT NUTRITION AT HOME OR COMMERCIALLY: GS Plant Foods sea kelp fertilizer is used extensively on a commercial basis, as well as at home for gardeners as an organic soil conditioner. Using GS Plant Foods seaweed plant fertilizer will lead to improved nutrient uptake and general plant wellbeing.
  • EASY TO APPLY FOR NATURAL GREAT RESULTS: Apply liquid kelp to improve growing conditions in all growth stages. This liquid kelp should be sprayed in the morning or late afternoon when temperatures are lower, and the leaves stoma are open.
  • TRUSTED & RELIABLE: At GS Plant Foods, we understand that you are placing your trust in us to provide you with the highest quality organic seaweed fertilizer products available. We have 100% confidence in the quality of our products and continuously strive to deliver the best customer experience. Our products are organic, easy to use, cost efficient, sustainable, and yield consistent & amazing results in your garden, no matter what you're growing or what medium in which your plants are growing.

GrassSoGreen Maintenance Liquid Lawn Fertilizer For Sprinkler System

American Hydro Systems 2655 GrassSoGreen Fertilizer, Maintenance Formula 19-0-0, 1 Gallon

This product from American Hydro Systems is specifically designed for application with sprinkler systems, but you can also use it with a garden sprayer or your hose pipe. The nitrogen-based formula contains no phosphorus so you can use in states that ban phosphorus in lawn fertilizers. Effective and easy to use, you can apply GrassSoGreen liquid fertilizer on cool-season and warm-season grasses for greener lawns without burning.

If you use this liquid concentrate fertilizer with your irrigation system, it gives your grass a nutrient boost every time you irrigate your lawn. This helps to keep the grass looking thicker and greener throughout the heat.

How to use the GrassSoGreen liquid lawn fertilizer: Originally designed to be used with the American Hydro GreenFeeder System, GrassSoGreen can be fed into any sprinkler system, either through an automatic injection or a siphoning system. This will then administer small, regular doses to the lawn. 


  • Designed for use with an irrigation system
  • Easy to apply throughout the year
  • Suitable for warm-season and cool-season grasses


  • Relatively expensive compared to other liquid fertilizers

What customers say: Customers of the GrassSoGreen liquid fertilizer loved how versatile this concentrate is. It can be used in a sprinkler system, with a garden hose pipe or sprayer.

American Hydro Systems 2655 GrassSoGreen Fertilizer, Maintenance Formula 19-0-0, 1 Gallon
  • ENVIRONMENTALLY FRIENDLY: GrassSoGreen Maintenance Formula is a nitrogen-rich naturally based fertilizer This environmentally friendly liquid fertilizer reduces over-application and run-off waste The 19-0-0 formula complies with all states that ban phosphorus in lawn fertilizers
  • EFFECTIVE: Gentle, yet effective, GrassSoGreen is versatile enough to apply to cool- and warm-season grasses You’ll get great results and a greener lawn -- and it won’t burn or leach out of soil like many other fertilizers ;
  • NITROGEN TECHNOLOGY: GrassSoGreen Maintenance Formula gives a boost of nutrients to your lawn every time you run your irrigation system The nitrogen technology helps grass green and promotes steady, sustainable growth throughout the watering season
  • THICKER, HEALTHIER LAWN: Formulated for maintaining a thicker, greener lawn, GrassSoGreen Maintenance Formula replaces nutrients lost due to mowing Used with your sprinkler system, it will keep your lawn looking great throughout the year
  • EASY TO USE: Designed for use with the American Hydro GreenFeeder System, GrassSoGreen can be fed into an irrigation system through an automatic injection or siphoning system so that small, frequent doses can be administered to the landscape Filling the tank is the only labor required ;

Organic Liquid Humic Acid Soil Conditioning Concentrate

GS Plant Foods Organic Liquid Humic Acid with Fulvic - Concentrate Fertilizer for Enhanced Nutrient Uptake and Soil Conditioning - 1 Gallon

As an all-purpose liquid humic acid, the GS Plant Foods organic liquid soil conditioner contains a formula based on Leonardite. The mix of fulvic acid and humic acid ensures that your grass roots can absorb the nutrients. It penetrates the soil and helps to stabilize the soil pH level as well as increase water retention. This leads to stronger roots and a stronger immune system of the grass plant. 

You should use this lawn soil conditioner in combination with another fertilizer. The application of humic acid can improve plant metabolism, allowing you to use less of your normal fertilizer. 

How to apply liquid humic acid concentrate: For the best results, mix two ounces of liquid humic acid concentrate with one gallon of water. Then apply the mix with a hose pipe or garden sprayer evenly across your lawn. Make sure that it gets as close to the grass roots as possible.


  • Ideal for a healthier lawn
  • Also works with houseplants, hydroponic gardens and trees
  • Affordable fertilizer supplement


  • Needs to be used with other fertilizers

What customers say: Users of the humic acid fertilizer are impressed with how quickly tired lawns grew rich, green grass. This feed can also be used for hydroponic gardens where it keeps the pH levels stable and supports strong root growth.

GS Plant Foods Organic Liquid Humic Acid with Fulvic - Concentrate Fertilizer for Enhanced Nutrient Uptake and Soil Conditioning - 1 Gallon
  • Versatile Humic Acid Concentrate: This organic liquid humic acid, derived from premium Leonardite, enables maximum nutrient absorption by directly reaching the roots, stabilizing soil pH and enhancing water retention.
  • Organic Super Fertilizer: Enhance plant immunity, metabolism, and root development while facilitating the accumulation of chlorophyll, sugar, amino acids, leading to a more efficient use of nitrogen and potentially reducing fertilizer rates.
  • Compatible with All Fertilizers: This top-tier humic and fulvic acid mix synergizes with all fertilizers except low pH or high liquid calcium ones, making it an ideal companion for gardens, houseplants, lawns, trees, greenhouses, crops, and pastures.
  • Easy Application, Remarkable Results: Mix the concentrate in water and apply as usual to the root base. Any sprayer works, but a hose-end sprayer is best for larger areas.
  • Trustworthy and Sustainable: GS Plant Foods is committed to delivering organic, cost-efficient, and easy-to-use products that consistently yield impressive results, perfect for various plant mediums. Made in the USA

Buying Guide For Liquid Lawn Fertilizer

There are many good reasons why you should choose a liquid fertilizer over a granular formula. We take a look at some of the main benefits of liquid lawn fertilizers, and how to apply them properly. 

Quick and Easy-to-apply Nutrients

The majority of liquid nitrogen fertilizers can be either applied by attaching them to a garden hose or you mix them with water in a watering can. Whatever way you choose, the application of liquid fertilizer concentrates is easy and takes only a few minutes.

However, you can get a more even and consistent spread of nutrients on your lawn when your spray the fertilizer. This ensures your entire lawn will get the same amount of fertilizer and no patch is left out. 

Good Value for Money

As liquid lawn feed is essentially highly concentrated, you can get a lot of use out of one bottle. It’s also lightweight and easy to carry, compared to granular fertilizers that come in large bags. This saves you not only a lot of effort but also money as you can cover a much larger lawn area with liquid fertilizer.

Acts Fast and Directly on the Grass Roots

Liquid fertilizers distribute nutrients directly to the grass roots as well as the surface of the lawn. This way the grass can absorb the nutrients quickly and much easier. In comparison, granular fertilizers act much slower as the granules need to be broken down and are released into the soil over time. 

What’s the Difference Between Liquid Lawn Fertilizers and Granular Fertilizers?

We already mentioned some of the benefits of liquid nitrogen fertilizers compared to granular feeds, including a much easier application, better value for money and absorption. This is why liquid concentrates have gained great popularity with gardeners in recent years. Here is a summary of some of the positives and negatives of liquid and granular fertilizers for your lawn.

Liquid Lawn Fertilizer Benefits

The greatest benefit of liquid lawn fertilizers is their liquid form. In gardens, water is much easier to distribute than anything else, so when you come to apply your lawn fertilizer you usually just attach it to your hose pipe and spray the grass. This ensures a uniform and even spread across the lawn.

The liquid form is also a plus for grass plants as they can absorb some nutrients, such as phosphorus, much better than solid granules. This quick-acting formula also makes liquid concentrates a firm favorite for landscapers and gardeners who have sewn a new lawn. 

On the other hand, if you don’t have a hose pipe (or some products even allow you to use fertilizers in a sprinkler system) you will need to apply the liquid in a garden sprayer which can take a little longer. 

While liquid fertilizers act fast on the grass, they also need much more frequent applications. As they are liquid, they can be easily washed away over time and the nutrients need to be restored to the grass. That’s why, some liquid fertilizers need to be applied as frequently as once a week which can be tedious, especially in the busy growing season.

Granular Lawn Fertilizer Benefits

Granular lawn fertilizer is the traditional feed option for your lawn. You can easily store it in bags or containers for long periods of time.

While you need a little bit more patience with granular fertilizer as it doesn’t act fast on grass, granules are slow releasing and don’t need as many applications as other fertilizers. Some products need even only one application per season. This makes them a great fertilizer for organised gardeners who want a more efficient fertilizer for their pre-planting time.

However, with slow-release fertilizer you run the risk of not applying it evenly across the lawn (even with a broadcast spreader, that’s difficult to achieve). This can lead to burning of the lawn and other plants as they cannot absorb the nutrients as quickly as liquid fertilizer.

How to Apply Liquid Fertilizer Concentrate to your Lawn?

You can apply liquid fertilizer in two ways, either by ground or foliar application. As the majority of liquid fertilizers are concentrated, you will need to dilute it with water.

Otherwise you may risk burning your lawn and plants. Some of the products we review were ready to go without mixing them with water, others required diluting, so it’s best you check the product label for instructions before you start. 

Also make sure that you shake the bottle well to blend the contents properly. This will avoid clogging the hose pipe or pump sprayer you are using for the application. If you have chosen a product that doesn’t come with a spray nozzle to attach your hose pipe, you can also use a garden hose sprayer or a hose-end sprayer.

A pump sprayer is a little more difficult to work as you essentially carry a small water tank with the diluted fertilizer on your back. As you need to add pressure to the tank by using the handle, you need to hold the wand and press the button to release the fertilizer. 

When you are ready to spray the fertilizer, you should start from the top end of your lawn and work your way down spraying in a side-to-side motion. This ensures the entire lawn area is covered and you don’t need to walk over the newly fertilized grass.

When Should I Apply Liquid Lawn Fertilizer?

When exactly you should apply the liquid fertilizer on your lawn depends on the product you have chosen. Read the instructions on the label first. Some fertilizer products are designed to be used either in spring and summer, while others can be applied all year round. It’s a good rule of thumb to apply fertilizer in spring as this is the best growing time for grass which means the plant can absorb all the nutrients well.  

If you want to use a fertilizer for spring and summer, you should give the first application in spring, with smaller doses applied every few weeks until early summer.

It’s important to keep in mind that the lawn soil should always be kept moist when fertilizing to ensure best absorption. Chemical liquid nitrogen fertilizers can burn your lawn in the summer season, so we recommend to use an organic liquid fertilizer in the summer months. 

How Much Liquid Fertilizer Should I Apply?

How much of the liquid fertilizer you should apply depends on the size of your lawn, and how many nutrients it needs throughout the year. If you apply too much you risk damaging the grass, whereas if you apply too little you won’t get the desired lush and green effect. 

Testing your soil

When you want to apply a fertilizer, it’s a good idea to understand more about your lawn and its soil. Try to use a soil test kit to find out how much nitrogen, potassium and phosphorus your lawn needs. These easy home test kits can measure the nutrients in your grass soil.

Once you know if there are any soil deficiencies, you can choose the right fertilizer to improve your lawn health.

Frequently Asked Questions

Is liquid lawn fertilizer better than granular?

Liquid fertilizer is a much cheaper and more effective lawn feed than granules. As liquid concentrates come in a bottle, they are easier to store and don’t take up much space. With liquid fertilizers, you can feed a much larger lawn area than with granular fertilizers. 

Can liquid fertilizer burn grass?

Liquid fertilizer can burn your grass in the summer months. Make sure that you always keep your lawn moist in hot temperatures, especially when fertilizing. This will help the grass to absorb the liquid fertilizer’s nutrients. Compared to granular fertilizers, liquid concentrates and lawn feeds are less prone to burning your grass as they act much faster.

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