A Shopping Guide to the Best Liquid Fertilizer for Plants

best liquid fertilizer for plants

You have taken good care of your plants for a while now. Yet, still, they look less vibrant and in need of some essential nutrients. The types of fertilizers required for your plants depend on several factors, some of them being the type of plant, the soil condition, weather, and so on. 

In this article, we will try to the find the best liquid fertilizer for plants.

While plants get their food from natural sources, a good liquid fertilizer will offer the essential micronutrients and beneficial microorganisms needed for optimum growth of your outdoor plants, indoor plants, as well as potted plants. Most plants are happy with an all-purpose fertilizer, though some plants need major nutrients and special care. 

Our Top Picks for Best Liquid Fertilizer for Plants

  1. MARPHYL Organic Liquid Fertilizer 
  2. Miracle-Gro Liquid All Purpose Plant Food Concentrate
  3. AeroGarden Liquid Nutrients for Plants
  4. Humboldts Secret Golden Tree: Best Plant Food for Plants & Trees 
  5. LawnStar Chelated Liquid Fertilizer for Plants 

Best Liquid Fertilizer for Plants

1. MARPHYL Organic Liquid Fertilizer

MARPHYL Marine Phytoplankton is liquid fertilizer catering to your outdoor and indoor plants. Great for your garden needs and hydroponics, this vegetable fertilizer, houseplant fertilizer, and lawn fertilizer is a storehouse of nutrients. 

This natural fertilizer is a great plant food that gives bountiful greens and colorful blooms and works well on flowers, vegetables, perennials, trees, shrubs, and herbs.

Marine phytoplankton is microalgae obtained from oceans. It is loaded with vitamins, minerals, essential fatty acids, DHA, EPA, amino acids, chlorophyll, and a vast spectrum of phytochemicals. The fertilizer enhances root growth and gives lively produce that makes your lawn, garden, and greenhouses look lush and beautiful. 

MARPHYL’s fertilizer offers nutritional benefits to enhance your plant’s defense mechanism, improve soil structure, and regulate water flow. 

The Marine Phytoplankton is an organic fertilizer, and environment-friendly plant food. It’s vegan, non-toxic, non-GMO & sustainable that is not loaded with preservatives, offering a safe environment for vegetable gardening, groundwater, and pets.

This natural fertilizer enriches your house plants, trees, and other greens with health and longevity. Rich in potassium, nitrogen, and phosphorus, as well as calcium and magnesium, your lawn and garden will be lush with healthy foliage, and your indoor plants will brighten your home.

Mix a 1:20 ratio with water. Once it is mixed thoroughly, sprinkle or pour it onto the plants. It can be used with both small and large sprayers. Use every two weeks, though the difference is noticeable after just one application.


  • 100% organic and non-toxic
  • Effective in 1-2 applications
  • Can be easily dissolved with water, no granules involved
  • Revives dying and withering plants


  • Emits a very bad smell
  • Destroys plants like Calatheas and Purple Passions

This Canadian non-chemical fertilizer is sourced from an area that is one of the most biologically productive marine ecosystems in the world. It is 120% sustainable.

View on Amazon


2. Miracle-Gro Liquid All Purpose Plant Food Concentrate

The Miracle-Gro Liquid is a concentrated formula of liquid plant food available in a 32 oz. can. This fertilizer instantly replenishes the plants such that your garden plants look vibrant and healthy. Just mix with water and feed your plants every 1-2 weeks. 

Miracle-Gro can be used as a foliar feed, soil drench, put directly on hydroponics, or simply added to your Miracle-Gro feeder or in your watering can. 

Miracle-Gro is easy to use and the liquid is packaged in a handy can. Just shake the bottle before use. Add the liquid as per package instructions to your watering can and use it by soaking the soil. 

12-4-8 is the fertilizer analysis or the ratio of nitrogen, phosphorus, and potassium in this plant food. The packaging says to mix one teaspoon into one gallon of water. There are 200 servings in this container. Some customers say it could last up to four years. 

If your plants are showing signs of weakening this plant fertilizer is for you. Miracle-Gro liquid can do wonders to turn around the health and vibrancy of the plant only in a short period. Dilute the plant food or there lies a risk of damaging the plants. 

It is suitable both as an outdoor and indoor plant fertilizer.


  • Easy to use, just mix in your watering can
  • Only a small quantity is required; they last a very long time
  • Value for money
  • Does not emit a foul smell


  • Customer reviews said that the product spoils plants like African Violets, Peace Lilies, or Pothos
  • If package instructions are not followed could burn the plants

Miracle grow is an excellent fertilizer for your house plants, flowers, trees, and all types of plants.

View on Amazon


3. AeroGarden Liquid Nutrients for Plants

AeroGarden is a liquid plant food that nurtures plants from seed-starting to vegetative growth, fruit, and flower blossoming. 

Available in an attractive container with smart packaging, this comes in a one-liter pack with 32 liquid ounces volume. At this size, you get more than 100 house plant feedings, which gives you good value for money. 

The food offers robust germination and growth as it contains a pH buffering system great for houseplants and all hydroponic gardening applications. Suitable for indoor gardening with the AeroGarden growing system, it provides water and food reminders to help plants thrive. 

This plant fertilizer is instantly available and improves the release of beneficial micronutrients to plants. While not exactly organic, here is what Aeogarden says about its product:

“AeroGrow uses the same proven, patented nutrients that we’ve used since the beginning – the result of 6 years of intensive testing in our grow rooms. Our nutrients contain no harmful pesticides or herbicides.

The FDA has procedures for classifying plants as organic, but nutrients are not regulated in this way. AeroGrow nutrients are made from mineral salts that provide iron, calcium, magnesium, and other “vitamins” that life on earth needs to flourish, in exactly the right amounts for your plants, derived from sources that ensure high levels of consistency and purity.”

You can pair the indoor plant food with the Easy Feed Plant Food Nutrient Dispenser (sold separately) that provides precise measurements in milliliters. Or, you can simply add the liquid to your watering can and water the soil around the plant for maximum seepage. 


  • Offers nutrition from the germination stage to later growth stages
  • Available in a handy can
  • Long-lasting for up to 100 feedings
  • Great for Aerogarden owners


  • Liquid spills a lot
  • Leaves sediment at the bottom

Aerogarden liquid nutrients are great for indoor plants, adding nutrients to houseplants for faster and consistent growth.

View on Amazon


4. Humboldts Secret Golden Tree Plant Food

Golden Tree’s formula makes professional-quality plant food to feed lawns, vegetable gardens, flower gardens, and plants. Available in concentrated forms, it is an all-in-one additive for any plant, tree, flower, or shrub. 

When used with a well-balanced fertilizer, Golden Tree helps improve soil/foliar nutrient conditions for the healthy growth of plants. Humboldts Secret Golden Tree solution is designed to be compatible in all mediums – hydroponics, aeroponics, coco, DWC, and soil.

Golden Tree supports plant and flower growth by providing nutrients to your garden that they are not receiving from the soil/water. The formula contains a mixture of kelp fertilizer, carbs, and minerals. It can be used in conjunction with other additives and fertilizers or on its own.

About one gallon of the solution makes up to 1,792 gallons of an easy-to-use additive solution for healthier plant growth. Use 1-3 times a week.


  • Great for hydroponics gardening
  • Can be used for a variety of plants
  • Affordable price
  • Available in a handy can
  • Can be used with other types of fertilizers and additives


  • Foul smell
  • Some customer reviews stated it was expensive
  • Burns plants when not used carefully

Golden Tree is a great plant additive that improves crop yields, supports conditions for better plant establishment and nutrient uptake, and aids in abiotic stress tolerance.

View on Amazon


5. LawnStar Chelated Liquid Iron for Plants

LawnStar Liquid Iron comes in a revamped model, though it still uses the same formula that customers have long relied upon. Complexed (or chelated) with sodium glucoheptonate, it gives your plants, greens, and trees stability and restores iron levels that help maintain garden foliage.

Liquid Iron treats symptoms of wilting and lackluster growth at the roots, helping revitalize your garden back to its former state. Iron is an essential nutrient that is the lifeblood of the plant. Plants rely on it for many vital functions: metabolism, chlorophyll production, and nitrogen-fixing to name a few.

Once applied, LawnStar Liquid Iron sends 6% highly-bioavailable iron nutrients right to your plant’s base. They immediately start working on reversing the iron deficiency that leads to leaf chlorosis, the yellowing of leaves that could eventually cause death in the plant.

The composition of nutrients in the soil also depends upon the pH value. High alkaline soil is the leading cause of iron deficiency. CLI’s sugar chelator ensures peak stability where other liquid irons don’t.

Use LawnStar Liquid Iron on your plants to restore a natural vibrancy and color to your plants. It also promotes stronger root development, builds a stronger foundation, and enhances stress tolerance. With this commercial-grade liquid iron fertilizer, you will get professional results. 


  • Safe to use — EDTA free
  • Tried and tested formula
  • Easy to use and effective
  • Customer reviews stated that the company provided useful information on the bottle packaging


  • The bottle had sediment deposits

LawnStar can be easily used for different types of plants and trees to restore their health and overcome iron deficiency.

View on Amazon


Differences Between Liquid Fertilizer and Granular Fertilizer

Liquid fertilizer is especially easy to use. Its application is just as easy as watering your lawn. Liquid fertilizers attach to your garden hose head for an even spray. 

They also distribute nutrients more evenly. You can put it in your watering can or the water supply for hydroponic plants.  

Liquid fertilizers are more concentrated than granular fertilizers with more nutrition packed in. Nutrients are nano-sized and are more easily absorbed by the plant. Very few nutrients are left behind with liquid fertilizers

In the liquid form, phosphorus, potassium, and other nutrients form a net neutral particle, which prevents conflict with other ions in the soil. This ensures extended availability to the plant.

Liquid fertilizers also have lower salt content, which makes them better as starter fertilizers. Granular fertilizers contain much more salt, and roots tend to steer away from granular fertilizers for this reason. If you are looking to fertilize germinating seeds, opt for liquid fertilizer. 

Organic vs. Synthetic Fertilizer

Organic fertilizers derive nutrients from natural sources of decay that release nutrients. For this reason, they are less likely to burn plants, but the downside is that organic ingredients are less potent, pricier, and emit a smelly odor not present in synthetics.

Synthetic fertilizers are stronger and nutritionally complete. Your plants will be happy with either. Plants don’t understand the difference between organic and synthetic fertilizers, they simply thrive with optimum nutrition. 

However, organic fertilizers are made up of natural ingredients that build up the soil, helping promote healthy microbial activity.

The USDA does not offer organic certifications for fertilizers as it does with organic foods. 


In looking for the best liquid fertilizer for plants, many of us get intimidated by the different types of fertilizers and their complex components. It seems easier to just replant our potted plants to save them from dying. 

However, with the above liquid fertilizers, you can ease your burden. Allow these products to take good care of your plants while you sit back and enjoy your garden’s growth and beauty.

Stay In Touch

Be the first to know about new arrivals and promotions