8 Best Fertilizers for Indoor Plants

Houseplant fertilizers aid in the nourishment of indoor plants by providing all of the nutrients they require. The ideal indoor plant fertilizers should include a balance of minerals to guarantee that plants have healthy roots, lush foliage, and beautiful blooms. Liquid plant food, rich granules, and slow-releasing pods are examples of houseplant fertilizers.
Houseplant popularity has skyrocketed over the last few years. A 2019 study shows that approximately 33.1 million households in the United States have at least one indoor plant. This means that you’re not the only one looking for the best fertilizer for houseplants.
Types of Fertilizer
Before determining the best fertilizers for indoor plants, we need to understand the different types of fertilizers.
- Liquid Fertilizer – Liquid fertilizer is the best option for plants with large blooms or plants that require frequent feeding. It is a great option to control the nutrient content your plants receive.
- Slow-Release Fertilizer – Slow-release fertilizer periodically releases nutrients into the soil, making it last longer. Usually the most expensive option due to its longevity.
- Granular Fertilizer – Granular fertilizer is a mixture of dry pellets that are incorporated into the soil. These are most common in outside plants but are safe for indoor plants.
All three of these types of fertilizer are perfect types of fertilizer to provide the best plant food for indoor plants. Still, choosing the best fertilizer for houseplants can be difficult. Luckily, we’re here to help you out. Keep reading to find out about some of the best fertilizers for indoor plants:
8 Best Fertilizers for Houseplants
Noot Organic Indoor Plant Food Liquid Fertilizer
Every watering, use Noot to keep your plants growing healthfully. Growing a green thumb is easier than ever before thanks to noot. Their improved formula has incorporated the world’s highest-quality strains of beneficial bacteria and friendly fungi that help your plants develop at their cellular level by forming a symbiotic connection with roots.
These microbes, which work quickly, need to be watered once and you will see them working. Other powders must be re-animated before they can start working and take more time.
Bloom City Organic Liquid Seaweed and Kelp Fertilizer

Finding the best organic fertilizer for indoor plants can be time-consuming since there are so many options to choose from. Based on our experience, Bloom City Organic Liquid Seaweed and Kelp fertilizer are one of the better options.
This product is formulated and made in the USA, which means there is less a chance for non-native chemicals or pesticides to reside in the formula.
Kelp provides aid for every growth stage of the plants ensuring the plants stay strong and healthy. Bloom City seaweed and kelp fertilizer contain seven species to ensure top-notch care for your plants.
Not only is this fertilizer safe for houseplants and vegetables, but also for lawn care.
Miracle-Gro Instant Release Liquid Plant Food

Miracle-Gro is a brand of plant soil and fertilizer that is known by most plant lovers, and for good reason. We believe it is worth all the hype with several different options on our list of the best plant fertilizer for indoor plants.
The liquid instant release plant fertilizer from Miracle-Gro is an instant way to give your indoor plants the feed they need to grow strong and healthy.
Because it is in liquid form, this type of fertilizer needs to be applied weekly. It is recommended to water your plants heavily after use to ensure the fertilizer is spread evenly.
One of the best features of the Miracle-Gro Instant Release Liquid plant food is that it is safe to use on edible plants.
Scotts Flower & Vegetable Slow-Release Plant Food

As with the other continuous-release fertilizer options, the Scotts Flower & Vegetable Slow-Release plant food keeps your indoor plants and vegetables happy for longer periods.
This fertilizer helps your plants grow strong roots and bountiful foliage by giving them the nutrients they need to promote healthy plants.
If used as directed, this product is safe and will not burn your plants as some fertilizers are prone to do.
The slow-release technology helps these granules to feed your houseplants for up to two months. Apply 1 cup of granules per 30 square feet directly from the bag, rake into 1 – 3 inches of topsoil and water; you’re all set!
Osmocote Smart-Release Plant Food Plus

Osmocote Smart-Release Plant Food Plus is designed to prompt strong root development and is a common choice among vegetable gardeners.
The high nutrient content of 14-14-14 makes it Ideal for perennials as the formula used for this product promotes vibrant colors in blooms and can feed up to 4 months.
Application is as simple as sprinkling 1 scoop of the plant food per 1 gallon into 4 square feet of soil then mixing with 1 – 3 inches of soil. Then water and watch the magic happen!
Miracle-Gro Indoor Plant Food Spikes

I always loved when my mom bought the Miracle-Gro Indoor Plant Food Spikes when I was a kid. For some reason, it was always so much fun to put the spikes in the soil. Maybe it was her way of getting me to help with the plants? Whether or not there was initial intent behind it, it worked.
The spikes feed flowering houseplants for up to 2 months and promote vibrate foliage. To use the fertilizer spikes, make a hole in moist soil halfway between the plant stem and the rim of the pot – Miracle-Gro has a tool that comes with these spikes to easily make this hole. Then place the plant food spike into the hole and cover it with soil.
The season will determine how often you need to replace the spike. Ensure to water your plant regularly to ensure optimal growth!
Marphyl Organic Liquid Soil Enhancer/Fertilizer

The Marphyl Organic Liquid Soil Enhancer/Fertilizer is made with all-natural marine phytoplankton. It is safe to use on plants, vegetables, flowers, lawns, trees, greenhouses, gardens, indoor plants, and hydroponics.
We love this product because it is 100% natural and does not include any GMOs. This product works by naturally boosting your plants’ health as it replenishes the nutrients in the soil.
Marphyl Organic Liquid Soil Enhancer/Fertilizer is highly concentrated and is recommended to use on plants every two weeks with a ratio of 1:20 with fresh water.
LiquiDirt All-Purpose Organic Powder

As the name suggests, this product comes in powder form, which is then mixed with water to supply up to 45 gallons of indoor plant food.
LiquiDirt All-Purpose Organic Powder is advertised as a full ecosystem in a bottle. It is an all-natural plant nutrient and supplement system that is made from a pH-balanced formula with 18 balanced super nutrients for plants.
Hand-made in the USA, LiquiDirt is 100% safe for pets and does not contain any odors as some other products do. One aspect we enjoy about this product is that it promotes growth for any plant you may have planted around the house.
FAQs
How often should I fertilize my indoor plants?
It varies from plant type to plant type, but generally speaking you should fertilize your plants about every three months.
How do I apply fertilizer to my houseplants?
You can use any type of spoon or measuring cup to apply your fertilizer. Always be sure to dilute it in water before adding it to the soil mix. You should also make sure your water is at room temperature. Bringing the water to a boil will damage the nutrients in the fertilizer and make it unusable for your plants.
What happens if I put too much fertilizer on my plant?
If you accidentally put too much fertilizer on your plant, be sure to wipe it out of the soil with water immediately. If you do not wipe it out, the soil could burn and damage your plant.
Can I use the same fertilizer I use for my outdoor plants?
No! The fertilizer you use for your outdoor plants is designed to be used in sunlight. The chemical reaction in the process of photosynthesis produces nutrients for the plant which are not produced when your plants are inside in dark areas.
What should I look for when buying houseplant fertilizer?
Look closely at the percentages of nitrogen, phosphorous, and potassium. The first number represents the percentage of nitrogen in the mix, while the second two numbers represent phosphorous and potassium respectively. In general, a 10-30-10 mix is good for most flowering plants.
How can I speed up my house plant growth?
You can speed up your house plant growth by placing them in a sunny location. We recommend that you fertilize once every 3 months and water twice a week.
Where can I buy fertilizer for my indoor plants?
You can buy fertilizer at any local garden supply store or you can buy fertilizer online here.
Conclusion
If you’re like me, you want to provide the best fertilizer for your plants to promote healthy growth. Fertilizers come in all shapes and sizes, making it difficult to know what product to select for your houseplants. Luckily, there are plenty of natural products out there that are safe to use indoors for your potted plants that enhance their growth. What fertilizer is your favorite?