Fertilizing Indoor Plants: The Best Fertilizer for Houseplants, When to Fertilize Houseplants, and How to Fertilize Houseplants


Fertilizing indoor plants is a process that must be done regularly to ensure your plants are healthy and thriving.

If you’re like most people, you probably fertilize your outdoor plants, but what about your indoor plants? Indoor plants need fertilizer too!

Being a houseplant parent is a pretty confusing and daunting routine. Unlike human babies, they don’t have a way to signal they are hungry or in need of nutrients until it may be too late. So instead, they respond to the environment in more subtle ways.

Fertilizing indoor plants is a process that must be done regularly to ensure your plants are healthy and thriving. However, not all houseplant fertilizers are created equal, so it’s essential to know which type of fertilizer is best for your houseplants.

This blog post will discuss the different types of houseplant fertilizers available, when to fertilize indoor plants, and how to fertilize them. We will also cover what happens when you over-fertilize a plant and how to avoid doing this.

So read on to learn more about fertilizing your indoor plants!

black and white photo of girl smiling with plant

What is the difference between types of Fertilizers?

There are different types of houseplant fertilizers in the market. Each is unique and will suit different types of houseplants. They are:

Liquid Fertilizer

Organic liquid houseplant fertilizers are the most popular and regularly used fertilizers by many plant growers. Using it is effortless as the application process requires putting it on plants, leaves, or soil. You can mix the fertilizer with water according to the prescribed measurements. Using water will enable you to add the fertilizer sparingly and avoid over-fertilization.

Liquid fertilizer is best for various houseplants as you can use large amounts of water to dilute very little fertilizer. However, experts recommend you apply it regularly for a duration of about 1 to 2 weeks.

Granular Fertilizer

Granular fertilizers are reliable and cost-effective alternatives to liquid fertilizers. Their application is relatively easy as you will simply sprinkle the granules on the soil, mix, or water them in. However, such an application is based on guesswork and can lead to over-fertilization.

It would be best to use granular fertilizer during planting or repotting to give it ample time to mix with water. Then, you can reapply it after every 4 to 6 weeks.

Slow-Release Fertilizer

Slow-release fertilizers come in various shapes and sizes. Some are pellets, while others are pods, spikes, and capsules. They are primarily available as traditional, not organic formulas. It is the best option for experienced plant owners who understand the various levels required by the particular plants.

girl with houseplants on a wall

How Much Liquid Fertilizer Does A Plant Need?

Every part has unique features, and this will vary their fertilization needs. Liquid fertilizer is a significant component that will help your plants grow fast with its ease of application. However, too much or too little will cause more damage than good.

After diluting the liquid fertilizer following the manufacturer’s directions, you will start the process of fertilizing your plants. Then, you can apply it directly to the plants’ leaves for faster absorption.

Every plant will require a fertilization schedule. Most require repeated fertilization for about 2-4 weeks. However, if your plants are healthier and sprouting as needed, it is best to wait until they reach the four-week mark.

The amount you apply to your plants will depend on the product specifications and type of houseplant. Always check the directions to enable you to get the proper measurements.

houseplants in sunroom
Our sunroom with lots of plants. I have a heater running during the winter to keep the plants warm.

The Best Fertilizer for Houseplants

The type of fertilizer you use will depend on the houseplant you have. We’ve matched common houseplants to their appropriate fertilizers and best practices. They include:

  • ZZ Plant Fertilizer

ZZ plants require 10-10-10 or 20-20-20 fertilizer monthly during the growing season, starting from spring to fall. Dilute the fertilizer to half of its strength as the typical fertilizer is too strong and will damage the ZZ plant foliage with its root systems.

The process is simple when you understand what you’re seeking. ZZ plants have a lot of leafy green growth and simple root systems that are susceptible to upset by watering. The typical fertilizer to use is Jack’s Classic All Purpose Fertilizer. It has a 20-20-20 mixture and requires dilutions to quarter strength before use.

Jack's Classic All Purpose Fertilizer
Jack’s Classic All Purpose Fertilizer

ZZ Houseplant Fertilizer

Jack's Classic All Purpose Fertilizer

Jack’s Classic All Purpose Fertilizer

  • Ideal for indoor and outdoor plants
  • Very easy to use with instructions
  • Fiddle Leaf Fig Fertilizer

The Fiddle leaf figs are common ornamental trees. They have large green foliage and require fertilizers with high nitrogen content to help encourage green leafy growth. They will thrive when presented with an NPK ratio of 3-1-2.

Fertilize your plant once in spring or monthly during summer. However, ensure you don’t overdo it. Furthermore, don’t fertilize them during winter as plants slow down their growth.

joyful dirt houseplant fertilizer bottle
  • Monstera Fertilizer

Getting an appropriate fertilizer for your Monstera plant will enable it to grow faster and more healthily.

Feeding your monsteras a precise balance of nutrients is crucial to their ability to grow year after year and produce luscious green leaves. Monsteras need a fertilizer with an NPK ratio of 5-2-3 that delivers all the key nutrients necessary to ensure strong root systems and healthy foliage growth.

monstera plant food fertilizer bottles
Monstera Plant Food

Monstera Fertilizer

monstera plant food fertilizer bottles

Monstera Plant Food

  • Perfect NPK Ratio
  • Natural & Gentle Formula
  • Made Specifically for Monsteras
  • Pothos Fertilizer

Pothos has an easygoing nature and lush foliage, making them a popular houseplant. You can enable them to grow bigger and beautifully green when you balance the nutrients on the proper schedule.

Luckily, they are not hungry houseplants. The best NPK ratio for Pothos fertilizer is 3-1-2, meaning there are about 3 times as much Nitrogen as Phosphorus and about 2 times as much Potassium as Phosphorus.

Feeding your plant with half of the fertilizer strength would be best. Start the process from Spring through Summer. Also, avoid putting in fertilizer in the Winter and Autumn months when most plants are dormant.

joyful dirt plant food
Joyful Dirt Plant Food

Pothos Fertilizer

joyful dirt fertilizer

Joyful Dirt

When to Fertilize Houseplants

It is best to fertilize your houseplants when they are actively growing. Most plants become dormant in the winter and autumn seasons, and feeding them at this time can kill or burn their foliage. Houseplants will wilt if they don’t get enough water. Their leaves turn pale and lanky if they don’t get enough sunlight. They can become dry and brittle if the humidity drops too low. If it is too high, they might develop rot. But, unlike watering and sunlight, it can be challenging to know when your houseplants should be fertilized.

Plants don’t give you a clear signal that it is time to fertilize. Other than slowing down or stopping growth, many houseplant parents often do not notice. So, instead of waiting for the plant to signal its time to fertilize, you will have to understand the growth cycle of your specific houseplant.

How Often to Fertilize Plants

Because houseplants and other containerized plants are confined to the soil in their pots, they can’t extend their roots and obtain additional nutrients once those nutrients run out. This is one of the reasons why it’s critical to use high-quality potting soil from the start, which often includes some slow-release fertilizer to help your plants get started. Adding more when this runs out or it is reported that the fresh mix will be vital. In addition, fertilizing your plants at least once a month will help keep them healthy and looking great during the Spring, Summer, and Fall.

As a rule of thumb, you should stop fertilizing your plants in the winter. However, you can fertilize houseplants every three weeks or even weekly during the summer because it is the most robust growing season.

Pro Tip: If you’re unsure how much fertilizer to give your potted plants, it’s always better to under-fertilize than go overboard. Organic Plant Fertilizers Vs. Inorganic Houseplant Fertilizer and Organic Plant Fertilizers organic plant fertilizers are derived from natural sources, such as animal manure, compost, and green manure. I am an organic gardener, and I only use organic fertilizers on my houseplants. I find they are gentler on the plants and don’t cause any burning or leaf scorching.


My favorite organic fertilizers are diluted coffee and fish emulsion, while my best inorganic plant fertilizers are made of synthetic materials, such as ammonium nitrate or urea. They are usually cheaper than organic fertilizers and release their nutrients faster.

What Are Some Homemade Natural Fertilizers I Can Use?

Do you want to use your home leftovers or household goods to give your plants a nutritional boost while saving cash? Try using the following items as natural fertilizer:

  • Eggshells: Save any unused eggshells, crush them, and boil them in a pan of water. Allow them to steep overnight before straining the liquid and applying it to your plants.
  • Diluted Coffee: Leftover coffee can be used as an organic natural fertilizer for most houseplants, and I highly recommend it! Just dilute it and use it!
  • Banana Peels: The potassium in banana peels is an ideal fertilizer for houseplants. Mash or cut the peel into several pieces and bury it in the soil surrounding your plant.
  • Aquarium water: Always save water by cleaning a freshwater fish tank for your plants. Fish water contains nutrients plants require for better growth.


1. What is the N-P-K ratio in fertilizer?

Several fertilizer packs feature the NPK number. Essentially, this is the ratio between the two most essential macronutrients that plants require: nitrogen.

2. What happens if you over-fertilize a houseplant?

If you fertilize too frequently or use too much fertilizer on your plants, they can become weak because their root system becomes damaged. You may also see leaves scorching or burning, and the plant may eventually die.

When fertilizing houseplants, it is essential to follow the recommended dosage on the fertilizer package and only to fertilize plants during their active growth phase. Also, be sure to water your plants thoroughly after fertilizing. And, as a rule of thumb, always do half what the package recommends. It is better to be safe than sorry!

closeup photo of spider plant

3. What are the risks of fertilizing houseplants?

Fertilizing houseplants can have risks, as too much of a good thing can be harmful. Over-fertilization can cause leaf scorching or burn, and the plant may eventually die.

Fertilize indoor plants with caution, and you will be rewarded with lush, healthy greenery that will brighten up any room in your home!

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