Best Overall

Bloom City Fertilizer Supplement

Credit: Amazon

Why You Should Get It

• This organic fertilizer is an eco-friendly, sustainably-harvested option that’s safe to use on any type of plants, including edibles.

Keep in Mind

• It has a strong seaweed smell that shoppers may not like.

If you’re looking for a plant food that’s made with natural ingredients, the Bloom City CleanKelp Fertilizer Supplement is the best option. Kelp boosts root and stem health—and when plants are healthier, they can better withstand environmental stressors like disease and insects. Plus, it’s much harder to burn your plants with an organic fertilizer.

Bloom City’s fertilizer is made with a blend of seven species of organic seaweed and kelp. It’s processed in order to extract the fibrous pulp that can create a brackish appearance.

It’s a good multipurpose formula; in addition to houseplants, you can use the fertilizer outside on vegetables, herbs, fruiting trees, and lawns. You can apply this to houseplants every time you water or once to twice a month if spraying outside.

Our tester used this fertilizer on their indoor plants, and the plants showed signs of improvement. While some fertilizers have a strong, unpleasant scent, we found that the smell of this one was appealing and somewhat sweet.

The only downside to this fertilizer is that unlike other options, like the Miracle-Gro Water Soluble All Purpose Plant Food, this one doesn’t come with a measuring tool. You may have to use an old measuring cup or spoon, or purchase one specifically to use for fertilizer. 

Product Details: Type: Liquid | Nutrient Levels: Not listed | Organic or Synthetic: Organic | Application Frequency: Every watering | Quantity: 32 ounces

• The Bloom City CleanKelp Plant Fertilizer is made with seven species of organic seaweed and kelp.
• Credit: Better Homes & Gardens
• The liquid solution can be either poured or sprayed onto plants.
• Credit: Better Homes & Gardens
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Key Terms to Know

• Macronutrients: The essential nutrients that your plants need to grow, including nitrogen, phosphorus, and potassium (these are listed as N-P-K ratios on the packaging).
• Granule fertilizer: A form of fertilizer that comes as a solid and dissolves during watering. These often come in powder, spike, or pellet form.
• Slow-release formula: Fertilizer that needs to be applied infrequently and slowly breaks down, dispersing nutrients gradually over time.

Best Budget

Miracle-Gro Miracle-Gro Plant Food

Credit: Amazon

Why You Should Get It

• This fertilizer promises to give indoor plants a good boost with its high nitrogen content.

Keep in Mind

• It’s not made with organic ingredients, so it’s not suitable for organic gardeners.

The Miracle-Gro Water-Soluble All-Purpose Plant Food is both budget-friendly and effective. Plus, you can use it on houseplants, flowers, vegetables, roses, trees, and shrubs, so you won’t have to buy more than one fertilizer to treat different plants in your home.

To use this fertilizer on houseplants, simply mix half a teaspoon of the liquid fertilizer with a gallon of water in a watering can and soak the base of your plants. You should plan to apply every one to two weeks during the growing season.

It’s important to note that the Miracle-Gro Water-Soluble All-Purpose Plant Food is made with synthetic ingredients rather than organic ones. This means they will eventually deplete the soil’s quality.

Over our testing period, our tester noticed that their mini ginseng tree grew at a faster rate than it had without the fertilizer, and the leaves doubled in size.

Since you only have to use a tablespoon each time, it'll last a long time, making it even more cost effective.

Product Details: Type: Liquid | Nutrient Levels: 24-8-16 | Organic or Synthetic: Synthetic | Application Frequency: Every one to two weeks | Quantity: 8 ounces

• The Miracle-Gro Water-Soluble All-Purpose Plant Food can be used on houseplants, flowers, and more.
• Credit: Better Homes & Gardens
• The fertilizer is easy to use and helped our plants grow over time.
• Credit: Better Homes & Gardens
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Best Liquid

Easy Peasy All Purpose Indoor Plant Food

Why You Should Get It

• A little goes a long way, so the 8 ounce bottle should last quite a while and feed many plants.

Keep in Mind

• It’s concentrated and must be added to water before use.

Many fertilizers are made for both indoor and outdoor plants. This isn’t an issue with proper application, but it’s common to over-fertilize indoor plants with this type of formula. The Easy Peasy All Purpose Indoor Plant Food is made specially for indoor plants to give you peace of mind.

Houseplants grow in poorer conditions than outdoor plants since they do not receive rainwater and constant sunshine, but this also means the environment isn’t stripping indoor plants of needed nutrients. Fertilizer helps replenish what the environment takes away, which means indoor plants do not need as many nutrients as outdoor plants.

Easy Peasy comes in a concentrated 8-ounce bottle and will need to be combined with water before use. It’s recommended to use 1 teaspoon of solution with at least 2 cups of water. When using this amount, you can get up to 12 gallons of food for your indoor plants.

The suggested frequency is once per week, but note that indoor foliage, cacti, and succulents need fewer nutrients than indoor plants with fruits or flowers. Keep this in mind when watering.

Product Details: Type: Liquid | Nutrient Level: 4-3-4 | Organic or Synthetic: Not listed | Application Frequency: Once a week | Quantity: 8 ounces

Best Slow-Release

Osmocote Plus Outdoor and Indoor Plant Food

Credit: Amazon

Why You Should Get It

• This fertilizer is the ultimate in low-maintenance gardening; apply it once, and it keeps working for four months.

Keep in Mind

• It’s made of synthetic ingredients rather than organic.

Don’t want to mess with fertilizing your houseplants very often? In that case, a great option for your indoor plants may be a slow-release fertilizer. Many of these fertilizers only require you to apply it every few months or just a couple times a year, minimizing the need for constant care.

Osmocote’s Smart-Release Plant Food keeps working for up to four months after you apply it. Although that may sound unbelievable, it works because each granule of the fertilizer is coated with a resin that controls how quickly the nutrients are released into the soil.

And since the nutrients in Osmocote’s fertilizer are released based on changes in temperature, the plant will receive more nutrients during the growing season (when they need them most).

It comes with the company’s no-burn pledge, which promises that your plants won’t get burned when you apply it at the recommended rate. Keep in mind that it is a synthetic product and not suitable for organic gardening.

To apply, sprinkle one scoop of fertilizer for every 2 gallons or 4 square feet of soil, mix it into the top 1 to 3 inches of soil, and then water as you normally would. The directions include appropriate amounts for different sizes of pots: for example, 1 teaspoon is recommended for an 8-inch pot.

Product Details: Type: Slow-release granules | Nutrient Levels: 15-9-12 | Organic or Synthetic: Synthetic | Application Frequency: Every four months | Quantity: 2 lbs.

Best All-Purpose

Dr. Earth All-Purpose Fertilizer

Credit: Amazon

Why You Should Get It

• If you want to buy just one type of fertilizer for your houseplants and outdoor garden, this one does the trick.

Keep in Mind

• It’s easy to overfeed with granule fertilizers, so follow the instructions carefully.

Instead of cluttering up your cupboards or gardening shed with tons of different fertilizers for every plant variety, consider buying an all-purpose fertilizer for your indoor plants.

The Dr. Earth All-Purpose Fertilizer can be applied to all your houseplants, then taken outside to treat your lawn and outdoor plants as well. Because it’s made with organic ingredients, you can also use it on your plants without as much concern about its impact on soil quality. 

For houseplants and container-grown plants, simply mix two heaping tablespoons of the fertilizer per gallon of soil (which is roughly equal to the soil in a 4-inch pot). You can mix this granular fertilizer in with the potting soil during planting or gently work the fertilizer into the top inch of soil for established plants.

This fertilizer provides a balanced mix of nutrients, which is what makes it so suitable for a wide array of plants. It's made from fish bone meal, alfalfa meal, fish meal, potassium sulfate, and kelp meal.

Use it once a month for houseplants and about once every eight weeks for flowers, trees, and shrubs. Granulated fertilizer can be very easy to over-apply, so be cautious not to feed your potted plants too much or too often.

Product Details: Type: Granule | Nutrient Levels: 4-6-5 | Organic or Synthetic: Organic | Application Frequency: Once a month | Quantity: 64 ounces

Best Granule

Burpee All Purpose Granular Plant Food

Credit: Amazon

Why You Should Get It

• The formula slowly dissolves to provide nutrients for up to three months, so you don’t need to apply it very often.

Keep In Mind

• It’s nutrient-rich and works for outdoor plants as well, which means it’s easy to over-fertilize.

The Burpee All Purpose Granular Plant Food feeds indoor plants for up to three months; each granule in the fertilizer is coated with resin to dissolve slowly and release nutrients over time.

Keep in mind that this pick can also be used for outdoor plants and is nutrient-rich, meaning it can be easy to over-apply for indoor plants. To avoid burnt roots or scorched leaves, use less than the recommended dosage for indoor plants, as too much fertilizer will negatively impact your plant’s health.

This pick can be mixed in with potting soil during planting or gently spread into the top inch of soil for established plants. 4 pounds of this fertilizer will cover over 200 square feet. You can use extra fertilizer in your outdoor flower beds, and be sure to store the bag in a cool, dry place.

Product Details: Type: Granule | Nutrient Level: 4-4-4 | Organic or Synthetic: Organic | Application Frequency: Every three months | Quantity: 4 lbs.

Best for Cacti and Succulents

The Grow Co Succulent & Cacti Plant Food

Credit: Amazon

Why You Should Get It

• It’s a highly low-maintenance fertilizer—each application should last for up to nine months.

Keep in Mind

• Pots deeper than four inches will require more pellets.

Cacti and succulents are optimal for anyone with a bad track record of keeping plants alive. They require minimal care, so it’s important to pick a fertilizer that fits in with that laid-back lifestyle.

The Grow Co Succulent & Cacti Plant Food is a low-maintenance pick. It serves as a nutrient booster and gently feeds your cacti and succulents over nine months.

The granular fertilizer is ideal for cacti and succulents because the slow-release pods are activated when watered, which means you avoid over-fertilizing.

To apply, sprinkle pellets onto the soil’s surface. The gentle formula is urea-free to prevent burnt roots, while the magnesium promotes vibrant color and a shiny appearance.

For best results, lightly mix the top layer of soil over the fertilizer. If you have pots deeper than 4 inches, keep in mind that ¼ teaspoon is required for every 2 inches of pot width. For larger cacti, this can get pricey.

Product Details: Type: Slow-release granules | Nutrient Level: 1-1-1 | Organic or Synthetic: Not listed | Application Frequency: Every eight to nine months | Quantity: 5 ounces

Best for Flowering Plants

EarthPods Fertilizer Spikes

Credit: Amazon

Why You Should Get It

• These plant fertilizer capsules are completely mess free; simply place them in the soil and let them dissolve slowly.

Keep in Mind

• You’ll need to use up to eight pods at a time for large plants, so you may run out of fertilizer more quickly than others.

To keep your indoor blooms vibrant and thriving for longer, purchase a fertilizer rich in nutrients that will help them develop their bright flowers. The EarthPods Organic Flower Food Fertilizer Spikes are designed for both indoor and outdoor flowering plants, and they’re super quick and easy to use.

Simply press one EarthPod capsule all the way into the potting soil mix near the center of the flowering plant, then water it as you would normally.

The Earth Pods will break down over time and slowly release nutrients directly into the soil near the root zone. You’ll need to reapply them every two to three weeks. These capsules can be used on flowering bulbs, houseplants, annual flowers, and flowering shrubs.

For small plants, you’ll only need one or two EarthPods, but you may need up to eight for large plants. To give your cut flowers an added boost, simply dissolve one or two capsules in a vase of lukewarm water and place the stems directly inside.

While many easy-to-use spikes, pellets, and fertilizer capsules contain synthetic ingredients, we like that the EarthPods Organic Flower Food Fertilizer spikes are made with organic ingredients. The packaging is even made from recycled paperboard printed with soy ink, minimizing this product’s long-term impact on the environment.

It’s important to note that the manufacturer doesn’t disclose the exact nutrient breakdown in its fertilizer capsules, so you won’t be able to compare it to other products based on its N-P-K contents. Be sure to follow the instructions carefully to ensure you don’t accidentally over-feed your plants.

Product Details: Type: Capsules | Nutrient Levels: Not Listed | Organic or Synthetic: Organic | Application Frequency: Every two to three weeks | Quantity: 4 ounces/100 capsules

Best for Herbs

Jobe’s Organics Plant Food for Herbs

Credit: Amazon

Why You Should Get It

• This fertilizer contains fungi to help break nutrients down and improve your soil’s quality.

Keep in Mind

• It has a strong lingering smell after applying.

Purchasing a fertilizer for plants you’ll ultimately be eating poses additional challenges, since you’ll want to ensure that the fertilizer won’t put you (or anyone who eats it) in danger. An organic fertilizer is a great choice for indoor herb plants, and we especially like Jobe’s Granular Plant Food for Herbs.

In general, herbs don’t require a ton of fertilizer, so this granular fertilizer contains 2% nitrogen, 5% phosphorus, and 3% potassium to give them an all-around boost. The phosphorus in particular helps it produce more greenery, resulting in more herbs for you to harvest and enjoy.

Additionally, the fertilizer also contains a blend of healthy bacteria and mycorrhizal fungi that help break down nutrients into the soil and improve the soil quality over time.

The product instructions recommend that you apply this fertilizer every four to six weeks. Because it’s a granular fertilizer, it can be easy to apply too much fertilizer, so follow the directions carefully.

Like most fertilizers, Jobe’s Organic Granular Plant Food has a strong smell. However, many gardeners reported that the scent lingers for a long time, so we recommend applying the fertilizer in a well-ventilated area for best results.

Product Details: Type: Granule | Nutrient Levels: 2-5-3 | Organic or Synthetic: Organic | Application Frequency: Every four to six weeks | Quantity: 4 lbs.

The Bottom Line

Our favorite fertilizer is the Bloom City CleanKelp Fertilizer Supplement because it’s easy to apply without spilling or burning your plants, and it uses natural ingredients instead of synthetic ones. For flowering plants, we love the EarthPods Organic Flower Food Fertilizer, which comes in the form of capsules that you can push into the soil.

What to Know About Fertilizers for Indoor Plants Before Shopping

Fertilizer Type

Fertilizers for indoor plants are available in three main forms: liquid, granular, and slow-release. Liquid fertilizers are diluted with water and applied through a watering can. No matter what form you choose, we recommend shopping for organic fertilizers over those with synthetic ingredients.

“Organic liquid fertilizers are my first choice for indoor plants because it’s easy to control the amount and frequency of their application,” Walliser says. “Plus, liquid fertilizers are available for plant use very quickly.”

Granule fertilizers are sprinkled on top of the soil and then mixed into the soil with water. This type of fertilizer is often less expensive than liquid or slow-release options, but it can be easy to apply too much fertilizer if you don’t follow the instructions carefully.

Slow-release fertilizers inject nutrients into the potting soil over an extended period of time. They may cost more than other types of fertilizer, but one application will last for several months, so you won’t need to re-apply as often. Many are made from synthetic rather than organic ingredients and they are available in several forms, such as pellets, spikes, pods, and capsules.

Nutrient Levels

As a general rule, the best fertilizers for indoor plants will provide a balanced level of nitrogen, phosphorus, and potassium, but not all houseplants will need the same nutrients.

Flowering plants will benefit from a fertilizer that’s high in phosphorus, which supports blooms, while young houseplants will do well with a fertilizer high in nitrogen that encourages healthy growth.

Organic or Synthetic

Traditional synthetic fertilizers may be a little more fast-acting than an organic one, but organic fertilizers are made with all-natural ingredients that’ll have better long-term effects.

To ensure that an organic fertilizer is safe for your organic garden, it’s a good idea to ensure it is OMRI-listed, which means it is approved by the Organic Materials Review Institute.

Suggested Frequency of Use

Always follow the manufacturer’s instructions when applying fertilizer to your plants—this is the best way to ensure you don’t over-apply it.

“If I’m using a liquid product, I fertilize my houseplants about once every four to six weeks from March through September while the plants are in an active state of growth,” Walliser says.

However, other types of fertilizers don't need to be applied as frequently. “If you’re using organic granular products or synthetic slow-release fertilizers, only apply once or twice from March to September,” Walliser says.

Keep in mind that houseplants need more fertilizer during the growing season and may have different needs during the winter months.

Type of Indoor Plant

Outdoor plants receive nutrients from the environment in addition to fertilizer, but indoor plants are not receiving that same sunshine and rainwater. That’s why fertilizer is so important to an indoor plant’s overall health.

Generally speaking, indoor plants can receive the same type of fertilizer as outdoor plants, but the amount and frequency will vary.

Plants with flowers or fruits will need more fertilizer, since picking the flowers or fruits takes nutrients away from the plant. On the other hand, foliage plants, cacti, and succulents will not need as much fertilizer.

Once you bring your new indoor plant home, a quick online search will show that specific plant’s needs. Just be sure to read the fertilizer’s instruction label; too much fertilizer can result in burnt roots and scorched leaves.

Your Questions, Answered

How much fertilizer do you need for a whole growing season?

The amount of fertilizer needed depends on the type of plant. Plants with flowers or fruits require more nutrients and may need new fertilizer every time you water. Some plants, including foliage and cacti, can go several months without new fertilizer.

It’s important to do quick research on your plant type and read the fertilizer’s label to ensure you aren’t giving your plant too much fertilizer as this can negatively impact your plant’s health.

Indoor plants’ growing season is from early spring to late summer. During these months, plants will benefit the most from fertilizer and receive the most nutrients, so prioritize fertilization during this time. Generally speaking, an 8-ounce fertilizer will last you one season.

What can you expect to pay for fertilizer for indoor plants?

The fertilizers on our list range in price from $6 to $40. Less expensive fertilizers are typically made from synthetic ingredients rather than organic ones. Over time, this can impact your plant’s soil quality. If you prefer organic or nutrient-dense fertilizers, expect to pay more.

If you have several indoor plants, you'll benefit from buying fertilizer in larger quantities since the price per ounce is typically lower in bulk. Plus, fertilizers stored in cool, dry places can last up to 10 years.

Who We Are

Renee Freemon Mulvihill is a writer who specializes in gardening and outdoor products, and Addie Morton is a contributing writer for Better Homes & Gardens who specializes in home decor and lifestyle content. To write this roundup of the best fertilizers for indoor plants, they researched products online, and Mulvihill spoke with Jessica Walliser, a horticulturist, author of Container Gardening Complete, and co-founder of SavvyGardening.com.