Last Updated on April 20, 2022 by Grow with Bovees
Growing indoor plants isn’t always as easy as it seems, because, as you are probably well aware, there are several factors that come into play for the successful growth of healthy flowering plants.
Just like you and me, indoor plants need to be fed and hydrated in a timely manner to thrive and grow well, and it all starts with choosing the best fertilizer for indoor plants.
Unlike outdoor plants that receive much of their nutrient intake from the sun and rain and are not in need of all purpose fertilizer, the nutrients provided to indoor plants are limited to the soil.
Even though some fortified potting soils are rich in minerals and other enhancements, you will have to fertilize the soil of indoor plants after a couple of months when the flowering plants have consumed all the available plant food in the soil.
Providing your plant with enough plant food is a basic part of good indoor plant care and is needed for successful plant growth.
We hope that this article will help you choose the best fertilizer for indoor plants, may they be flowering plants, edible plants or foliage plants.
9 Best Indoor Plant Fertilizers
Miracle-Gro Indoor Plant Food — Best Spray Fertilizer for Plants
The Miracle-Gro indoor plant food is a great liquid plant fertilizer to use with all types of indoor plants. These include edible plants, green foliage plants and flowering plants, a hoya krimson queen or African violets for example.
This type of liquid plant food comes in a handy spray bottle, and contains 1 percent nitrogen, 1 percent phosphate, and 1 percent potash.
This plant fertilizer is easy to use, and ready to apply as soon as it arrives. When applied, it has the ability to feed your plants instantly, boosting beautiful and healthy plant growth.
When fertilizing indoor plants, Miracle-Gro indoor plant food can be applied either directly to the soil or it can be mixed into water and added while watering your potted plants.
Add to Soil
When adding this plant fertilizer directly to potting soil to feed plants, the Miracle-Gro spray indoor plant fertilizer for plants should be sprayed twice for small pots, and 5 sprays should be applied for larger pots, to ensure that it reaches the plant roots.
Feed indoor plants with this liquid houseplant fertilizer at least once a week for satisfactory results. Water as usual after application of fertilizer.
Mix in Water
If you choose to mix this liquid fertilizer to water before applying it, simply add 4 pumps of the solution in the spray bottle to every quart of water that you are using, followed by watering the plant as per usual.
Jobe’s Houseplant Indoor Fertilizer — Best Spikes for Active Growth
Jobe’s houseplant fertilizer spikes offer a great balance of nitrogen and other minerals.
Indoor plant food spikes are an easy way to keep your houseplants healthy and deliver a continuous supply of nutrients right at the roots of the plant.
These pre-measured specially formulated spikes can be simply inserted into the soil around your houseplants.
The NPK ratio of Jobe’s spikes is 13:4:5, making it a great choice for all your indoor plants.
This smart release plant food is one of the better quality fertilizers available today that unlike liquid and granular fertilizers eliminates messes, hazards, and smells, and does not wash away when you add cups of water.
Jobe’s spikes should be applied every 8 weeks, and each package contains 50 spikes.
Joyful Dirt Organic Premium Concentrated Houseplant Fertilizer — Best Concentrated Fertilizer
For an organic balanced fertilizer that contains beneficial microbes as well, you really can’t go wrong with the Joyful Dirt organic concentrated fertilizer for indoor container plants.
It is one of the few organic fertilizers that is specially formulated to feed all kinds of green leafy plants kept indoors but is not recommended for use on outdoor plants.
The Joyful Dirt organic fertilizer comes in a convenient shaker bottle for easy application to your indoor potted plants.
Application to Soil
You can either apply this indoor plant food directly onto the soil by sprinkling a small amount — about ⅛ of a teaspoon for the average plant — of the product on each side of the plants, followed by normal water.
Mix into Water
You can also opt to mix it directly into your watering can. Simply mix one teaspoon together with ½ a gallon of water and stir it together for about 30 seconds. This makes enough to water about ten plants. Water the plant as usual during application.
The Joyful Dirt concentrated organic fertilizer is to be applied once a month, and a little more often if you are treating unhealthy plants.
It contains Mycorrhizae, and other growth enhancers, and has a 3-1-2 N-P-K ratio. This nutritional mixture helps the potted plant thrive and use less water. This product can be used on all types of indoor plants.
The Joyful Dirt fertilizer is safe to use around kids and pets and claims to produce more vibrant and larger houseplants showing quick results after application.
The Grow Co Fiddle Leaf Fig Tree Liquid Plant Food — Best Fig Food
The Grow Co Fig Tree plant food offers a continuous supply of nutrients for all ficus varieties. These include Ficus lyrata (fiddle leaf), Ficus elastica (rubber tree/rubber plant), Ficus audrey, Ficus benjamina (weeping fig), Ficus religiosa (sacred fig), Alli (narrow leaf) and many more.
This water soluble fertilizer product contains all natural and safe organic ingredients to help in the growth of strong and tall fiddle leaf trees.
The slow-release element promotes strong root growth, and the right amount of vitamins and minerals for your outdoor and indoor potted plants, resulting in beautiful plants on your property. It promotes the growth of sturdy branches, beautiful leaves and generally promotes better health.
The Grow Co slow-release fertilizer is a great alternative to liquid fertilizer and is an easy-to-use formula that greatly reduces fertilizer burns in indoor and outdoor plants.
Simply mix this product with water and add it to your plants. After just a single application, this plant food feeds your ficus trees for up to six months and can be mixed with the top couple of inches of the soil.
LiquiDirt Nano Organic All-Purpose Fertilizer — Best Organic Fertilizer for Leaf Shine and Brown Leaf Tips
The LiquiDirt fertilizer is an organic indoor plant food that has an all-natural ingredient list and is — in out opinion — the best organic fertilizer to use for indoor plants.
These organic ingredients include poultry, litter, rabbit manure, bat guano, worm castings, humic shale, oyster shell, and kelp meal.
This organic, nutrient-rich all-purpose plant food can be used for all types of plants including heavy feeders and is a pH-balanced formula.
LiquiDirt all-purpose plant food does not expire ever and stays good until you use it, and is made based on the company’s Zymology process.
This power fertilizer is 100 percent water-soluble and should be added to water to make a super concentrate. It is the perfect product for organic gardening.
Benefits of This Product
This product comes with a few benefits for your houseplants. These include:
- It makes for roughly 6400 applications for indoor houseplants, with every gallon of the solution being enough for 128 applications.
- It claims to be an ecosystem bottled up in a concentrated formula.
- It is easy to apply to your plants.
- This product is suitable for all soil types and growing media, as well as semi hydro, hydroponics, terrariums, lecca, fish tanks, water gardens, flowers and much more.
- It is beneficial to the healthy growth of stems, foliage, roots, blooms and overall plant health.
Osmocote PotShots Slow-Release Fertilizer — Best Slow-Release Fertilizer
Osmocote PotShots is one of the best slow-release fertilizers in the market and is specially formulated for potted plants.
These pre-measured food nuggets contain a great blend of essential nutrients and due to its amazing slow release formula, it can feed most indoor plants and outdoor container plants for up to six months.
This slow-release organic liquid organic houseplant fertilizer should be used twice per year, during the growing season, making it an easy and convenient way of feeding your houseplants.
Osmocote PotShots liquid plant food contains homogeneous granules topped with a proprietary slow-release coating derived from soybean oil, which ensures great nutrient absorption for your plants.
Each package of this indoor plant food contains 25 nuggets, and each nugget should be placed halfway between the edge of the container and your plant’s stem.
Lastly, push each nugget one to three inches deep into the soil, and then water as usual.
Miracle-Gro Spikes — Great For Flowering Plants
Unlike the Miracle-Gro liquid plant food mentioned above, Miracle-Gro indoor plant food spikes are a perfect choice for the continuous feeding of plants.
This (2 Pack) Miracle-Gro offers great value for money, given that you get not one but two-2.2 ounce packages.
These plant food spikes are billed as one of the best fertilizers for houseplants, and its primary macronutrients are geared towards creating strong roots and boosting plant growth in houseplants including ferns, pothos, spider plants and croton.
When applied to your common houseplant properly, Miracle-Gro spikes will last up to 2 months.
This smart release plant food should be replaced every 30 days in the spring and summer, and every 60 days in the winter and fall.
Each spike should be planted in each hole of moist soil and pushed down until it is covered by the soil.
It features a 6:12:6 N-P-K ratio and is a great choice for all indoor flowering plants and foliage houseplants.
Alaska fish liquid fertilizer is infused with nutrients derived from fish to provide your houseplants with strong, healthy, and natural growth.
Apart from slowly releasing fertilizer to your plants, Alaska fish fertilizer also considerably improves your soil’s structure and condition.
This fish-based fertilizer is available in a plastic bottle and is great for use in vegetable and flower gardens.
It has a 5-1-1 NPK ratio and is OMRI listed for organic gardening.
If you have beautiful philodendrons growing in your home, Philodendron Fertilizer is your best friend.
This nitrogen fertilizer of this indoor plant fertilizer has a 3-1-2 NPK ratio and is formulated to deliver nutrients to the soil and roots of your houseplants.
It’s a good choice for many varieties of philodendrons including velvet philodendrons and philo pink princess.
Philodendron Fertilizer is nutrient-rich and comes in an 8 Oz bottle.
This 8-ounce bottle lasts roughly a year and should be used once a month during the months of good sun. In cooler climates, during the months of winter, apply this fertilizer once every six weeks instead of once every month.
To mix it, simply add one teaspoon of the fertilizer and mix it with two cups of water, followed by watering your plant as directed.
This concludes our choices for the best indoor plant fertilizers. Continue on for more general information on indoor plant fertilizers.
What’s In Houseplant Fertilizers?
High-quality house plant fertilizers contain a great mineral balance of both micro and macro-nutrients.
These essential minerals are represented by the NPK ratio-nitrogen, phosphorus, and potassium, and are listed on the label of the respective fertilizer.
An excess mineral ratio can affect the growth of plants, which is why it is highly important to pay attention to the amounts of nutrients in the fertilizer.
Adding to this, the ratio of nutrients found in the best organic lawn fertilizer is different from the NPK ratio of houseplant fertilizer, because these two groups of plants have different nutrient needs.
This means that you shouldn’t use a lawn fertilizer to feed your houseplants, because it will probably not result in healthy growth.
The N-P-K Ratio of Organic Fertilizers
To break down the NPK ratio, the middle number stands for phosphorus, a macronutrient that’s essential for flowering.
So, if you have flowering houseplants, you should look for a fertilizer with a slightly higher amount of phosphorus for active growth.
Contrarily, if you have non-flowering houseplants, buy a fertilizer that’s slightly higher in nitrogen (first number).
Apart from these critical nutrients, some fertilizers contain both micro-nutrients like iron, zinc, and boron, and macronutrients such as calcium and magnesium.
Although micronutrients are present in smaller amounts than macronutrients, these crucial nutrients are important for the growth of roots and growth of stems and leaves in certain plants.
Types of Indoor Plant Fertilizer
Now that you’re aware of the essential nutrients in houseplant fertilizers, it’s time to know about the different types of fertilizer for indoor plants available to determine which one is right for you.
There are myriad different varieties of indoor fertilizers to choose from-sticks, liquids, tablets, granules, fast and slow-release forms, making it tricky to get the right one for your indoor plants.
Synthetic fertilizers are typically made of synthetic chemicals and are known to be fast-acting products. They can be purchased in a variety of forms. These forms include granule, liquid, spike and pellet form.
These types of fertilizers are also often classified as water soluble fertilizers which means that they can be absorbed by plants almost immediately after application, providing the plants with a quick nutrient boost which increases the greening of foliage.
While this is a great aspect of the synthetic fertilizer, one should know that the lovely green color will not last as long as when you use organically manufactured fertilizer. This results in the plant owner having to apply the product more frequently to hinder the color from fading.
Another disadvantage of chemical fertilizers is that it does not do much to stimulate healthy soil. It does not better soil structure or texture nor does it affect the long-term fertility status of the soil. Their high water solubility means that the chemicals can easily leak into nearby waterways and applying too much of these types of fertilizers may cause your plants to burn.
Fertilizers that are classified as being organic simply means that they are made from organic sources. Organic fertilizers are great to use, as they will provide great benefits to both the soil and your plants.
Organic indoor plant food benefits the soil by improving its structure as well as stimulating beneficial soil microbes to grow, which are necessary when it comes to converting the fertilizer into nutrients that are soluble in order for them to be taken up by the roots of the plants.
What is great about an organic fertilizer as opposed to a synthetic fertilizer, is that it often provides shrubs with essential micronutrients that they need for healthy growth.
The NPK ratio of organically manufactured fertilizers is often lower than the chemical ones, but with a slow release formula is able to provide food for plants over a longer period of time. The impact is more subtle and the result takes a bit longer, but in the end you will be rewarded with plants that stay greener for longer.
Liquid Fertilizer for Houseplants
Liquids are the most common, cost-effective fertilizers, and simply need to be diluted with a little or a lot of water depending on your plant’s healthy growth needs.
But on the downside, many liquid fertilizers need to be used more frequently than their granular counterparts, but, on a brighter note, offer a reduced risk of fertilizer burn.
There are several types of houseplant fertilizers available, but the preferred choice for most avid gardeners is Miracle-Gro or organic fertilizer for houseplants and trees.
Even though organic liquid fertilizers take a bit longer to work, they do provide a steady stream of nutrients, making them a great solution to feed your indoor houseplants.
Adding to this, they are also easier to control, meaning you can stop feeding when the plant goes dormant in the winter months, and continue feeding during the period of active growth.
Granular Houseplant Fertilizer
Granular fertilizer comes in the form of pellets, and works well during active growth periods.
They can be mixed with potting soil by hand, and are most commonly used in outdoor gardens, but can also be used in indoor plant containers.
Granular fertilizer is available as granular pellets or compressed spikes, where the former are sprinkled on the surface of the soil, and the latter pushed down into the soil to get in close contact with the roots of the plant.
Just like liquid fertilizers, there are both organic and chemical granular fertilizer options available, but again, organic is an excellent choice for most indoor gardeners.
Granular organic plant fertilizer contains naturally derived ingredients such as sulfate of potash, dehydrated worm castings, blood meal, bone meal, rock phosphate, limestone, and plant-based natural ingredients.
If the label on the container of fertilizer doesn’t have an ingredient list of all the nutrients, then great chances are that it’s a synthetic concentration of fertilizer.
Granules are best used when repotting a plant in fresh potting soil, and release essential nutrients when you water the plant.
The water aids with nutrient absorption by transporting the granular fertilizer from the top layer of potting soil to the root zone of the plants.
Slow-release Houseplant Fertilizers
Just as the name would suggest, slow-release fertilizers offer gradual fertilizer delivery to the houseplants.
Also dubbed time-release fertilizers, slow-release fertilizers contain a synthetic source of nutrients that are tucked away in a coating.
This coating gradually breaks down and slowly releases the nutrients in low doses over a long period of time, so you will have to feed them only a couple of times or so per year.
Slow-release fertilizer bottles and packages are a highly convenient way to feed houseplants, but most do not contain eco-friendly ingredients.
When to Fertilize Houseplants?
Now that you know about the different types of fertilizer options available to feed houseplants, it’s important to figure out when to fertilize indoor plants.
Determining when to fertilize indoor plants is actually fairly easy, and the rule of thumb is to fertilize after the first frost to prepare your houseplants for the spring and summer ahead.
Houseplants generally go dormant or semi-dormant during the winter, and therefore they do not need fertilizer.
If you fertilize houseplants at this time, the plants will not absorb the nutrients, and in fact, will make them more susceptible to diseases and insects.
However, this also depends on the type of houseplant, because ones that continuously grow through the winter, such as aloe vera and snake plants, should be fertilized less at the rate of ½ or ¼ as much in the winter as you would in the summer.
Start feeding dormant and semi-dormant plants at the end of February.
Adding fertilizer to potting soil may not be a good idea unless the label says it’s safe to go this route, because most potting soils often have fertilizer in them, and adding more could result in fertilizer burn.
How Often to Fertilize Indoor Plants?
It is recommended that you feed plants by following the instructions on the fertilizer label, and how often you should fertilize indoor plants boils down to the fertilizer you’re using.
If you’re feeding liquid fertilizer, some products should be used just once or twice a month, and others each time you water the houseplants.
You should also pay attention to the ratio of fertilizer to cups of water, which is usually indicated clearly on most fertilizer labels.
Granular fertilizers need to be applied more frequently because they release quickly into the soil, hence are digested by the plants more quickly.
Slow-release fertilizers, spikes, and pods tend to last a couple of months or more, depending on how much you use, and the size of your indoor plants. Again, for all types of fertilizers, follow the manufacturer’s usage instructions.
How to Fertilize Indoor Plants?
How much fertilizer to use and how to apply it exactly depends on the type of fertilizer you’re using, but here are some general guidelines.
Using Liquid Fertilizers
Fertilizers that are liquids are available in several NPK ratios and can be mixed with any other nutrients your soil needs.
You usually don’t need to use a lot of liquid fertilizer, but a teaspoon or a tablespoon should be enough.
Some liquid fertilizers can be applied directly to the green leaves of your houseplants, whereas others are meant to be applied directly to the roots.
Using Organic Fertilizers
Organic liquid fertilizers are generally concentrated, so you will have to make a diluted solution and spray either on the roots or leaves of the plants for effective nutrient absorption.
Using Granular Fertilizers
With granular fertilizers, you have to first and, most importantly, measure carefully, and then mix into the top one or two inches of soil.
As mentioned earlier, the nutrients of granular fertilizers are absorbed pretty quickly by indoor plants, so make sure you feed enough granules for the entire root system.
Granular fertilizers can also be mixed in with fresh soil when transplanting or repotting a plant, but read the manufacturer’s directions before use.
Using Slow-Release Fertilizers
Slow-release fertilizers should be inserted directly and should be placed a couple of inches into the soil.
Feeding houseplants can be tricky, and knowing when to feed them can be even more challenging. Finding the best fertilizer, whether it be the best water soluble fertilizer or the best synthetic fertilizer or a completely different product is also not an easy task.
There are several ways to tell if your plants need fertilizer or plant food, such as wilting, pale, and lanky leaves.
The best indoor plant fertilizers depend on your houseplant’s needs, so choosing the right fertilizer for indoor plants can be confusing.
The good news is that most of the common houseplants have similar feeding needs, but some blooming plants can be heavier feeders than others.
With regards to the schedule of plant fertilizers, it’s best to refer to the instructions on the label before application.
Compost tea is a great source of nutrients, but it doesn’t always make the best indoor plant food due to the fact that it often stinks terrible! It’s better used for fertilizing plants outside rather than on your tropical plants indoors.
Some of the best fertilizers for indoor plants are available in a bottle for storage purposes and easy use, whereas others come in sealed packages.
As long as you use the right products, fertilizing houseplants, whether it be a flowering plant or a foliage plant, is an easy task.