Top 10 Best Liquid Fertilizer For Indoor Plants 2023 [Detailed Reviews & FAQs)

Last Updated on March 9, 2023 by masudalam

For your indoor plants to thrive well, providing them with balanced nutrition is the only way to help achieve it. One of the best options that you can use to feed well your indoor plants is to help with fertilizer. If you want to ensure your indoor plant’s health you should find a balanced fertilizer which contain minerals and nutrients.

There are different types of fertilizer that you can use as a house plant fertilizer such as liquid, nutrient-rich granules or slow-releasing pods. With this in mind, here is the complete guide on learning how to select the available option. Also, there is a detailed review of the best houseplant fertilizer you can choose as one of the best options.

Types Of Indoor Plant Fertilizers

There are three main types of indoor plants fertilizer that you can use for your indoor plants. The fertilizer includes:

  • Liquid indoor fertilizer – These are the kinds of fertilizers that you are in liquid form or have to add to the water when watering your plants.
  • Granular indoor plant fertilizer – This is a type of fertilizer that you have to mix with the soil on the base of your plant so that it can release nutrients to your plant.
  • Slow releasing fertilizer – It is one kind of fertilizer that gradually releases its nutrients into the soil.

The Best Type To Choose For Indoor Plants

When choosing the best type of fertilizer for your indoor plants, some factors can influence your choice. Some of the factors that may determine the type of fertilizer to use include soil type, application method, type of the plants. However, in general, the organic indoor liquid fertilizer is one of your best options since it is to apply and control and, at the same time, can provide essential nutrients to your plants.

Note that if you are planting flowering plants, go for the organic liquid fertilizer with a higher proportion of phosphorus. For the non-flowering indoor plants, go for the liquid fertilizer with a high nitrogen ratio.

Now we will explore the ten best liquid fertilizers for indoor plants that you can use. So let’s look at the list in more detail.

1. Humboldts Secret– World’s Best Liquid Nutrient/Fertilizer for Indoor Plants

It is one of the best liquid fertilizers for indoor plants that contains a complete nutrient system. The fertilizer contains a mixture of the macro and micronutrients that your indoor plants may require for healthy growth. You can use the fertilizer from the beginning of the indoor plant growth to the end of the flowering or growth of your plant.


  • It contains all the plant’s nutrients that your plant may require
  • It is easy to use
  • It is suitable for different types of plants
  • It is garden friendly
  • It is appropriate fertilizer.


  • It has a craze acidic, so you need to watch the amount you apply to avoid raising the PH.

2. Easy Peasy Plants House Plant 4-3-4 Plant Nutrients

It is another best liquid fertilizer for houseplants that comes with a nutrient ratio specifically designed for indoor plants. This liquid fertilizer is well balanced since it promotes vegetative growth and colorful and regular flowering. Since it is a fast-acting fertilizer, it can help your plant develop strong roots and make your plant strong and look healthy.


  • Suitable for a wide range of plants variety
  • It is highly concentrated, and with little fertilizer, you can gain a huge promising result.
  • It is affordable.


  • It releases its nutrients very fast; therefore, you will have to apply the fertilizer periodical
  • It is a highly concentrated fertilizer so applying it too much on your plant can cause burn to your plants

3. Liquid Silica Boost Fertilizer and Supplement 2.5 Gallon (320 oz)

If you are looking for a liquid fertilizer that will protect your indoors from extreme conditions, this is an ideal option for you. The fertilizer boost and strengthens the plant’s cell wall making it strong and keeping it growing despite any challenging condition. The fertilizer is of high quality and adds a lot of value to your plants because it results in healthier plants throughout the plant life cycle.


  • It helps in boosting the strength of your indoor plants
  • It contains the essential nutrients that might be useful to your indoor plant
  • It compatible with different kinds of nutrients system
  • It offers protection to your plant during harsh conditions


  • It has high levels of toxins.

4. Purived All-Natural Liquid Fertilizer for Indoor Plants | for Potted Houseplants |

Do you want all-natural best liquid fertilizer for indoor plants without any chemicals? The fertilizer has a balanced mixture of micro and macronutrients essential for feeding your plant throughout its life cycle. This fertilizer will surely provide your plant with balanced nutrients to boost its health and attain vibrant growth.


  • It is a versatile fertilizer, and you can use it for outdoor and indoor plants.
  • It is highly soluble in water, making the hungry plant absorb the nutrients as quickly as possible once you apply them to your plants.
  • It is a long-lasting fertilizer.


  • It is highly concentrated, and if it is not applied incorrect amount, it can scorch your plant

5. All-Purpose Indoor Plant Food, Great for pothos, Peace Lily, Spider Plant, Ferns, Palms, ficus, African Violets, Cactus.

Is it ideal liquid plant fertilizer that is correctly formulated and does not have any scorching or burning effect on your indoor plant? The fertilizer is an organic and natural formulated, and you should not worry about chemical residue that would, in turn, affect your plant. Also, the fertilizer is premix; therefore is ready for use fertilizer.


  • It is a natural fertilizer, so it is safe to use
  • It is suitable for indoor plants
  • It is easy to use
  • It contains all the nutrients plants may require


  • It is expensive

6. OMRI Listed Hydrolyzed Organic Liquid Fish Fertilizer for Plants (1 Gallon)

It is another best liquid fertilizer for all-natural indoor plants that is an excellent option for growing indoor plants. The fertilizer is made from an organic mixture, and it has all the nutrients that you may find in inorganic fertilizer. However, the difference between this fertilizer the synthetic fertilizer is that they provide more nutrients and are more suitable for the plants. With this fertilizer, your plant will grow faster with less maintenance.


  • It is easy to use or apply
  • It provides optimal growth and healthy plant
  • It comprises micro and macronutrients
  • It is a reliable and trusted brand
  • It is an all-natural fertilizer


  • It is stinky.

7. 18-3-6 Liquid Fertilizer (50% SRN & Micronutrients) (2.5 Gallons)

It is an all-purpose liquid fertilizer that you can use on your plant in all-season or plant life cycle. The fertilizer is a slow-realizing fertilizer containing nutrients that can aid your indoor plant growth and overall health. Note that this fertilizer has a long-term effect on the plant, so even a single application will do wonders to your plant. However, depending on the plant and soil you have, you can apply the fertilizer for at least two weeks.


  • t all-purpose fertilizer
  • Contain the essential nutrients
  • It is easy to use
  • It is economical fertilizer since it releases the nutrients slowly to the plant
  • Long-lasting effect
  • Boast plant’s growth and development


  • It does not immediately impact the plant.

8. MARPHYL Organic Liquid Fertilizer – Outdoor & Indoor Plant Food – All-Purpose

The fertilizer is designed in a way that can boost the plant’s natural health. The fertilizer is made from marine Phytoplankton full of minerals, vitamins, and nutrients. Also, the fertilizer is multipurpose because you can use it either indoors or outdoor on a wide range of plant varieties.


  • t is an all-natural liquid fertilizer
  • It is a versatile fertilizer suitable for both indoor and outdoor plant
  • They are highly soluble in water, making them easy to apply to water.
  • They are suitable and safe to use
  • They promote soil quality
  • They promote the plant growth and development


  • Expensive

9. FoxFarm Grow Big Soil Liquid Concentrate Fertilizer, 1 Gallon

It is an active and water-soluble fertilizer designed to boost the blooming and flowering traits of your plants. The fertilizer is an organic fertilizer and naturally made that can instantly provide the nutrient that your plant may require. With this fertilizer, your plant will enhance multiple or extra-large blooms. The fertilizer is compatible with various types of irrigation systems, and you can use folia sprayer, drip irrigation, or hydroponic systems without causing any damage to your plant.


  • It is an instant acting fertilizer
  • Perfect for fruit or flowering production
  • The best option for indoor plants
  • It is easy to use
  • Suitable for all growing conditions


  • It does not have a long-lasting effect

10. Kelp Fertilizer by GS Plant Foods (5 Gallon) – Organic Liquid Fertilizer for Gardens, Lawns

It is among the top ten best liquid fertilizers for indoor plants in this list, and it comes with many benefits. The fertilizer is an organic fertilizer that feeds the plant with natural nutrients to enhance plant growth and health. This fertilizer acts as a miracle food because once you apply it to your plant, the plant gains some traits that make it survive in challenging conditions since the plant stability is established. The plant can stay healthy thought its lifecycle.


  • It is an organic indoor liquid fertilizer
  • It does not have any harmful chemicals
  • It provides optimum health and plant growth
  • It is a trusted and reliable brand
  • It is easy to apply
  • The fertilizer gives great results through all the growth stages


  • It has short term effects

Things To Consider Before Buying Best Liquid Fertilizer For Indoor Plants

When you want to buy plant fertilizer, especially the indoor ones, do not assume it to be an easy task since there are several things that you need to factor in since these fertilizers do not have the same performance. Here are the main things to consider when buying the best liquid fertilizer for indoor plants.

a) N-P-K ratio

For a better houseplant fertilizer, you should make sure that you go for the fertilizer that has the highest or equal proportion of nitrogen, phosphorus, and potassium. For instance, an NPK ratio of 10-10-10 would be better because it indicates that the fertilizer has an equal mixture of the three major nutrients that they would require most by your indoor plant.

b) Healthy Nutrients

Not all the nutrients found in fertilizer are healthy, especially inorganic fertilizer. To ensure that you get fertilizer with healthy nutrients, go for natural or organic fertilizer. With the Healthy nutrients, your plant will be able to get all the necessary food they require without posing any adverse effects to the plants.

c) Organic or Synthetic

Organic fertilizers are manufactured from natural sources, while synthetic ones are derived from chemical substances. Though the two fertilizers may contain the same proportion of nutrients required by the plant for growth and development, synthetic ones are not good for your plant, so you should avoid them. Once the chemical builds up in the soil, it will, in turn, affect your plant.

Frequently Asked Questions on Indoor Plant Fertilizer (FAQs)

1. Why indoor plants require fertilizer

Since most indoor plants will be planted in pots, bags, or a closed area like a greenhouse, regular feeding is required to ensure that the soil has all the nutrients that can be used for the growth and development of the plant. Therefore, you will need fertilizer for indoor plants to get healthier plants and boost reproduction, flow, air purification, and soil quality.

2. Is there any drawback to using organic fertilizers for indoor plants?

Yes, there are different drawbacks that you can get when using organic fertilizer for indoor plants. Some of the major drawbacks include:

  • Organic fertilizers have different nutritional mixture levels, which may lead to inconsistent indoor growth and development.
  • Most of them are not as active as synthetic fertilizer, which can affect the plant later on in the plant’s growth cycle. Therefore frequently application of the fertilizer may be required.
  • Preparation of organic fertilizer has a complicated procedure, and it is time-consuming.

3. When to Fertilize Indoor Plants?

Fertilized houseplants tend to grow in summer and spring actively. Therefore, you should start applying the fertilizer at the start of spring and continue until late summer if necessary, depending on the type of crop you are growing. Note that you should stop the application of the fertilizer during the fall and winter. Because the indoor plants tend to remain dormant during this period, note that applying the fertilizer during the early stage of the plant will help a lot since it enhances the plant’s health development and growth.

4. How to use liquid fertilizer for indoor plants?

The application depends on the type of fertilizer and plant you have. Some of the fertilizer comes as premix, which you can apply to the plant, but for others, you have to read the instructions on what content you must mix with water for a given plant. If the fertilizer you have is all-purpose fertilizer, you will have to directly apply it to the soil without splashing it on the leaves. But for the folia one, which is designed for the leaf application, you can spray on the leaf using a bottle sprayer or any sprayer you have after you prepare the solution.

5. What’s in indoor plant fertilizer?

The indoor plant fertilizer contains macro and micronutrients. The primary nutrients are nitrogen, phosphorus, and potassium, while some minor nutrients include iron, zinc, calcium, magnesium, boron, and others.

Final thoughts

Note that picking the best liquid fertilizer for indoor plants is not always easy. Even though the fertilizer comes with labels, picking one might also be challenging if you do not know what works for indoor plants. You should learn more about your plant, and when it comes to the choice using the knowledge you have to learn today, you will be able to pick the right one.

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