Boost Your Lawn with the Best Liquid Fertilizer for Grass

A liquid fertilizer for a grass is a fertilizer meant to be mixed with water and then sprayed across the grass to improve its health and growth. Most fertilizers include a mix of nitrogen, phosphorus, and potassium, which grass (and other plants) use to fuel themselves. Out of all of the products reviewed, GS Plant Foods Liquid Kelp was the best because it includes a balanced ratio of the critical three nutrients. It’s made from kelp and promotes root growth and general chlorophyll development.

A single bottle of the Liquid Kelp can cover up to 10,000 sq. ft., and can be applied every 10 days. Overall, it’s inexpensive, easy to use, and contains just about everything grass could need to be healthy and beautiful. For more information on the Liquid Kelp, see our Product Reviews section below.

The runner-up liquid fertilizer is Simple Lawn Solutions 16-4-8 Balanced NPK. It’s not as good as the GS Plant Foods Liquid Kelp because it doesn’t cover nearly as much surface area and doesn’t seem to produce the same deepening of color and root lengthening as the GS.

However, this product was tested on multiple grass types and is pretty inexpensive. It includes the main crucial ingredients of nitrogen, phosphorus, and potassium, and it also has potash and humates. It would work well for someone who only wants to treat their lawn once a month rather than every 10 days and would like the inclusion of a nozzle. For more information on the Simple Lawn Solutions, see our Product Reviews below.

The best budget liquid fertilizer is the Just Scentsational TPW-1Q Trident’s Pride Liquid Fish Soil Fertilizer. A container can cover 2,500 sq. ft. when used properly and only costs around $17 for a single gallon. It comes with a nozzle, is simple to use, and can be used with pesticides. The main downside people might run into is that it does smell strongly of fish, which can be off-putting until the fertilizer dries. However, it is extremely inexpensive and only needs to be applied once a month, so it works well for people who are on a budget. To read more on the Trident’s Pride, see below.

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Liquid Fertilizer Buyer’s Guide

Fertilizer Chemical Ratios

There are three primary chemicals that strongly boost plant growth: Nitrogen, Phosphate, and Potash. Depending on your specific needs, and the plants you’re trying to grow, you’ll want to purchase the formula of fertilizer that most closely matches your requirements. If you don’t know what your lawn needs for a fertilizer, it’s best to pick up a soil test kit to determine which formula is best for your specific location and environment. A soil moisture meter may be helpful as well!

Spray Types

Foliar Spray

Foliar fertilization involves spraying fertilizer directly on the leaves of a plant. The leaves absorb fertilizer quite rapidly and potently through the stomata, small pores in the leaves similar to the pores on a human’s skin. These stomata act as ports for fertilizer uptake. Foliar sprayers come in a variety of different designs. Some connect up to a garden hose and mix water directly in line with the fertilizer, while others are simple cans that apply pre-mixed and diluted liquid fertilizers. Depending on your needs and the specific fertilizer, you’ll want to pick up the foliar sprayer that’s appropriate for your needs.

Root Feeder

Root feeders supply fertilizer directly to the roots of the plants, bypassing the leaves. Depending on what plants you’re attempting to fertilize, you may want to use a root feeder as opposed to a foliar spray.

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Liquid Grass Fertilizer Reviews

In this section, we’ll look at six different Liquid Lawn Fertilizers. We’ll compare and contrast the different options, and pick our favorites. To get the lay of the land, we’ll start with a comparison table, and then move onto the individual brands and products.

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American Hydro Systems F4G-1: Grass So Green

Key Features at a Glance

• 1 Gallon Covers 2,000 sq. ft.
• Targets Grass and Turf
• Eliminates weeds
• Made from 30% Bio Builder
• Organic-based
• Fertilizer Formula: 7% Nitrogen, 7% Phosphate, 7% Potash

Dimensions and Specs

Comes in containers of 1 or 4 gallons

Weighs roughly 10 lbs.

1 Gallon covers 2,000 sq. ft.

Needs to be used with the ProFeeder, Green Feeder or Green Feeder Mini

Grass So Green provides lush, even coverage across the surface area of a lawn. It includes natural and organic ingredients designed to fertilize plants and soil for healthy growth. The fertilizer uses something from American Hydro Systems called Bio Builder, which includes humates and organic compounds. These humates are a crucial part of fertilization and are substances containing humic and fulvic acid that nourish plantlife and soil health. Grass So Green is easy to use and comes in a simple white jug that includes a cap designed for easy pouring into a sprinkler or feeder system. Like other liquid fertilizers, Grass So Green needs to be mixed with water according to the specifications on the bottle. However, unlike most of the other liquid fertilizers on our list, it is designed primarily to tie into your existing sprinkler system, and not to be used with backpack sprayers. If you don’t have this sort of lawn, you’ll want to skip this one. The Grass So Green mixes in with your sprinkler water using one of their feeder systems (like the Green Feeder here). It works great and takes most of the thought out of fertilizing, but it only works for those who have sprinkler systems.

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Simple Lawn Solutions 16-4-8 Balanced NPK

Basic Features

• Contains Seaweed and Fish
• Made in the United States
• Works on Multiple Grass Types
• Uses Natural and Organic Ingredients
• Contains 16% Nitrogen, 4% Phosphate, and 8% Potash

Dimensions and Specs

Comes in a 1-quart bottle with sprayer

1 quart treats 3,200 sq. ft.

1 quart costs $25

Simple Lawn Solutions 16-4-8 Balanced NPK is a liquid fertilizer for grass that comes with an attached spraying nozzle. It can be used by hand or poured into a sprinkler or feeder system for maximum coverage. The formula is a mix of nitrogen, phosphate, and potash designed to provide nutrients both to grasses and soil. The fertilizer has demonstrated its effectiveness on numerous grass types, including Bermuda, Kentucky Bluegrass, and Ryegrass. It works on warm and cool season variations. The fertilizer can be applied once a month and should not be used on rainy days to prevent seepage and ensure effectiveness. Once it has dried, the fertilizer is safe for children and pets. It should not be touched when wet. Some of the ingredients include seaweed, fish, and other organic compounds like humates. It does not include any harsh chemicals or pesticides. The 16-4-8 Balanced NPK, like other liquid fertilizers, must be mixed with water during use. The solution comes in a 1-quart bottle and should treat 3,200 sq. ft. The attached nozzle connects to standard garden hoses so users can mix the fertilizer with water while spraying. As noted by the name, the NPK ratio is 16-4-8.

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GS Plant Foods Liquid Kelp Organic Seaweed Fertilizer

Basic Features

• Made from Seaweed
• Made in the United States
• Can Be Applied Frequently
• Supposed to Improve Root Growth and Health
• Works on Grass, Shrubs, and Flowers
• Ratio: Nitrogen 1.0% Phosphorus 0.23% Potash 0.6%

Dimensions and Specs

Comes in 1-gallon containers

Can be sprayed once every 10 days

One bottle covers 10,000 sq. ft.

The GS Plant Foods Liquid Kelp is made from the seaweed plant Ascophyllum Nodosu and contains a potent mixture of nitrogen, phosphorus, and potassium. It comes in single gallon containers that are made of simple white plastic. Some form of application method is required but does not come with the fertilizer, so users will need to invest in sprinklers or a feeder. This Liquid Kelp should be mixed at a ratio of 1-2 oz. of fertilizer to 1 gallon of water for maximum efficiency. A single container can cover up to 10,000 sq. ft. and the fertilizer can be reapplied every 10 days for maximum effectiveness. It works on grass and many of the surrounding plant life, including trees, shrubs, and flowers. It’s supposed to improve the output of plants, which means grass might become darker, thicker, and fuller after regular applications. GS Plant Foods fertilizer appears to do a variety of services for grass. It can increase the amount of chlorophyll storage in the grass, helps relieve the stress from extreme weather conditions, and improves root growth so the grass is stronger and healthier. It should also increase the number of microorganisms found in the soil, which improves the production of natural byproducts (like nitrogen) needed for healthy grass growth. Liquid Kelp is safe for children and pets once dried but should be avoided when wet. It shouldn’t be sprayed on rainy days because the rain can ruin absorption. As there is no built-in sprayer and mixing valve on the bottle, you’ll have to apply it with a separate bottle and mix it yourself.

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Just Scentsational TPW-1Q Trident’s Pride Liquid Fish Soil Fertilizer

Basic Features

• Made from Fish
• 100% Organic Ingredients
• NPK Ratio of 2-3-1
• Benefits the Earthworm Population
• Improves Root Growth

Dimensions and Specs

Comes in 32 oz. containers

Comes with a spraying nozzle

One bottle covers up to 2,500 sq. ft.

The Just Scentsational Liquid Fish Fertilizer nourishes soil and grass using a combination of nitrogen, phosphorus, and potassium in a 2-3-1 ratio. The mixture includes fish remnants for extra proteins, and enzymes designed to seep into the soil and stimulate grass growth and root health. This fertilizer additionally benefits the earthworm population by providing additional nutrients and sustenance, which gets them to work harder and produce byproducts that again stimulate grass growth. It’s almost like a worm composter and fertilizer in one! Like some other liquid fertilizers, Just Scentsational comes with a spraying nozzle which the user can connect to a standard garden hose for maximum effectiveness in covering yards. A single 32 oz. container should cover around 2,500 sq. ft. and needs to be applied roughly once a month. It should not be touched when wet but is alright for children and pets upon drying. All of the ingredients are organic and no pesticides are included. The total NPK ratio of the product is roughly 2-3-1, and the Just Scentsational should improve root growth, depending on your needs. The bottles of fertilizer are a cloudy white and the liquid is dark brown. It can be mixed with weed killers and pesticides so long as users follow the instructions on the bottle.

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Scotts Turfbuilder Liquid Starter Lawn Fertilizer

Key Points at a Glance

• Works on any grass type
• Should feed and water simultaneously
• Contains nitrogen and potash

Dimensions and Specs

Comes with a spraying nozzle

One bottle covers 2,000 sq. ft.

Attaches to a hose

Container holds 32 oz.

Scott’s Turfbuilder Liquid Starter Lawn Fertilizer is supposed to fertilize and improve the appearance of grass through a combination of nitrogen (around 29%) and potash (around 1%). It feeds and waters simultaneously, and the bottle comes with a nozzle for easy hose attachment and spraying. A single 32 oz. bottle should be enough to cover 2,000 sq. ft. and can be applied once a month for maximum effectiveness. Scott’s liquid lawn fertilizer has been tested on multiple grass types throughout the United States and was found to be effective on all of them. It should make grass greener and stronger but needs to be kept away from flowers, shrubs, and other plants. The fertilizer should not be touched when wet and needs to be kept away from children and pets. This stuff is not organic. The manufacturer recommends spraying on dry days to avoid runoff and to give the fertilizer time to soak in the soil.

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Simple Lawn Solutions Extreme Grass Growth Lawn Booster

Basic Features

• Enriched with fulvic and humic acid
• Contains nitrogen and phosphorus
• Non-toxic
• Works on multiple grass types
• Made in the USA

Dimensions and Specs

Container holds 32 oz.

1 bottle treats 3,200 sq. ft.

Comes with an attached sprayer

Connects to a hose

Simple Lawn Solutions Extreme Grass Growth Lawn Booster is a liquid grass fertilizer which comes in a translucent bottle holding 32 oz. The solution covers roughly 3,2000 sq. ft. This package includes a simple nozzle that can be attached to a plain garden hose for spraying. Each bottle is relatively inexpensive and is manufactured in the United States to ensure quality control. This liquid fertilizer primarily contains fulvic and humic acids to promote grass growth and root development. Other ingredients include a mixture of the big three ingredients: nitrogen, phosphorus, and potash (though potash is almost nonexistent). The mixture works well on new seed or sod as well as established grass. Some of the species of grass it has been tested on include Buffalo, Centipede, St. Augustine, Bermuda, Bluegrass, and Palmetto. The Extreme Grass Growth Lawn Booster is completely non-toxic and environmentally friendly. This fertilizer should be applied 7-10 days after any form of weedkiller is used. It works best when applied every three weeks or once a month, and the wet formula should be allowed to dry. The manufacturer recommends that users avoid spraying the Extreme Grass Growth Lawn Booster on days when it will rain or is humid out.

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Simple Lawn Solutions Intense Green Grass Enhancing Booster

Basic Features

• Works on multiple grass types
• Non-toxic
• Made in the United States
• Includes nitrogen and phosphorus
• Produces almost no odor

Dimensions and Specs

Each container covers 3,200 sq. ft.

1 bottle holds 32 oz.

Comes with a nozzle

Connects to a hose

Simple Lawn Solutions Intense Green Grass Enhancing Booster, along with being a mouthful to say, is an effective liquid fertilizer for grass that makes use of popular ingredients like nitrogen. The liquid produces almost no odor and comes in 32 oz. containers with attached nozzles. The nozzles connect to standard garden hoses and make it easy for users to spray the fertilizer around their lawn. A single bottle should cover 3,200 sq. ft. This fertilizer is non-toxic and should be safe for children and pets once dry. It should be applied on dry days once every three or four weeks. The manufacturers encourage individuals to not use the fertilizer on days when it will rain or particularly humid ones because the fertilizer might fail to soak into the soil. The Intense Green Grass Enhancing Booster strengthens grass, detoxifies soil, improves chlorophyll production, provides nutrients, and can also deepen the green shade of a lawn. Simple Solutions tested their product on a broad range of grasses including Buffalo, Centipede, St. Augustine, Bermuda, Bluegrass, and Palmetto. The fertilizer is environmentally friendly and can be used all year long. A single bottle can last for a reasonable amount of time and is not terribly expensive. It should not be applied at the same time as a weed killer. Lawn owners should wait at least a week before adding liquid fertilizer to grass.

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Conclusion: Best Liquid Grass Fertilizer

So, Liquid Kelp is the clear winner because it can be used often, covers a lot of surface area, and works on multiple plants. It even improves the appearance of grass in more noticeable ways than the other products. As a runner-up, the Simple Lawn Solutions 16-4-8 is a balanced choice if a little expensive, and the budget option of Just Scentsational is great as well if people can handle the fishy smell. All function well, so the main decision of a buyer is going to be affected by what they need, what they want to spend, and how big their lawn is.

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