Best Overall
Bloom City Fertilizer Supplement
- This organic fertilizer is an eco-friendly, sustainably-harvested option that’s safe to use on any type of plants, including edibles.
This organic fertilizer is an eco-friendly, sustainably-harvested option that’s safe to use on any type of plants, including edibles.
- It has a strong seaweed smell that shoppers may not like.
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.
To apply it to your indoor plants, mix 5 to 10 milliliters per gallon of water in your watering can and pour the solution over the soil. You can also spray it on the leaves if you are applying it to a lot of plants or in a large area.
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.
We tested this fertilizer on our indoor plants, and we were pleased that our 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 fertilizer comes in a container with a lid that we had to push down and twist to open, so it would be difficult for children or pets to get into it. Because the formula is organic, we also appreciated that we could use it on edible plants, such as herbs and vegetables.
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
- BETTER HOMES and GARDENS / ERIC BROCKOB
BETTER HOMES and GARDENS / ERIC BROCKOB
Best Budget
Miracle-Gro Miracle-Gro Plant Food
- This fertilizer promises to give indoor plants a good boost with its high nitrogen content.
This fertilizer promises to give indoor plants a good boost with its high nitrogen content.
- It’s not made with organic ingredients, so it’s not suitable for organic gardeners.
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. Be sure to follow the instructions carefully to avoid applying too much and burning your plants. For outdoor plants, you can use more of the fertilizer: 1 tablespoon of fertilizer per gallon of water.
This formula is relatively potent, providing 24% nitrogen, 8% phosphorus, and 16% potassium. This is a good amount more than a number of other fertilizers designed for houseplants. The high concentration of nitrogen can help foliage plants grow, and the phosphorus will give flowering plants a boost, too.
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. People who prefer to use organic fertilizers for indoor plants will want to avoid this option.
When we tested this fertilizer on our own indoor plants, we appreciated how easy it was to use. We mixed a tablespoon of the blue granules with a gallon of water and fertilized our plants. Over our testing period, we noticed that our mini ginseng tree grew at a faster rate than it had without the fertilizer, and the leaves doubled in size.
We also liked that we only had to use a tablespoon each time—the fertilizer is also an affordable price, and the fact that we only had to use a little bit means it will also 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
- BETTER HOMES and GARDENS / ERIC BROCKOB
BETTER HOMES and GARDENS / ERIC BROCKOB
Best Spikes
Jobe’s Fertilizer Spikes
- These spikes are easy to use—you can insert them into the soil in your houseplant’s container and forget about it.
These spikes are easy to use—you can insert them into the soil in your houseplant’s container and forget about it.
- It can be easy to overfeed your plants with this type of fertilizer, so be sure to follow the instructions carefully and err on the side of caution.
It can be easy to overfeed your plants with this type of fertilizer, so be sure to follow the instructions carefully and err on the side of caution.
The best fertilizer for indoor plants should be easy to use, and we love that Jobe’s Indoor Beautiful Houseplants Food Spikes make plant care nearly effortless. Just insert the spikes into the soil around the plant, halfway between the stem and the edge of the pot.
Compared to some liquid fertilizers that have to be applied at every watering, these spikes are a very low-maintenance option, and you only need to add new spikes every 60 days.
After you insert the spike, the nutrients are gradually released into the soil over time without you needing to do anything more. Plus, the nutrients are released near the roots—right where the plants need them most.
The directions on the packaging tell you how many spikes are needed based on the diameter of your pot, which will help prevent you from accidentally overfeeding your plant.
These fertilizer spikes provide 13% nitrogen, 4% phosphorus, and 5% potassium. The high nitrogen level should help increase foliage growth substantially. Although this product doesn’t have as much phosphorus as some fertilizers, it should work well for flowering houseplants too.
Keep in mind that over-feeding your plants with this type of fertilizer will cause them to wilt, turn brown, and lose their leaves. Make sure not to add a new spike to your soil for at least 60 days to avoid over-fertilizing your houseplants. It’s also important to note that these spikes are designed for houseplants, not vegetables or outdoor plants.
Product Details: Type: Granule (spikes) | Nutrient Levels: 13-4-5 | Organic or Synthetic: Synthetic | Application Frequency: Every 60 days | Quantity: 0.01 ounces/30 spikes
Best Granule
Burpee All Purpose Granular Plant Food
- The formula slowly dissolves to provide nutrients for up to three months, so you don’t need to apply it very often.
The formula slowly dissolves to provide nutrients for up to three months, so you don’t need to apply it very often.
- It’s nutrient-rich and works for outdoor plants as well, which means it’s easy to over-fertilize.
It’s nutrient-rich and works for outdoor plants as well, which means it’s easy to over-fertilize.
The best fertilizer for indoor plants provides nutrients for your plants and is low-maintenance for you. 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. Plus, the organic formula, which contains 4% nitrogen, 4% phosphorous, and 4% potassium, promotes soil health.
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.
Walliser recommends only applying organic granular fertilizer once or twice from March to September. This will help your plant absorb the most nutrients during the growing season and prevent over-fertilizing.
This pick can be mixed in with potting soil during planting or gently spread into the top inch of soil for established plants. Four 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 pounds
Best Liquid
Easy Peasy All Purpose Indoor Plant Food
- A little goes a long way, so the 8 ounce bottle should last quite a while and feed many plants.
A little goes a long way, so the 8 ounce bottle should last quite a while and feed many plants.
- It’s concentrated and must be added to water before use.
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.
A proper formula can make all the difference for your indoor plants and ensure their health isn’t negatively impacted. Liquid fertilizer is easy to apply, and there’s a smaller chance that you accidentally over-fertilize and burn your 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
- This fertilizer is the ultimate in low-maintenance gardening; apply it once, and it keeps working for four months.
This fertilizer is the ultimate in low-maintenance gardening; apply it once, and it keeps working for four months.
- It’s made of synthetic ingredients rather than organic.
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).
This fertilizer contains 15% nitrogen, 9% phosphorus, and 12% potassium, and it works for many different plant varieties and growing conditions. It also 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 pounds
Best All-Purpose
Dr. Earth All-Purpose Fertilizer
- If you want to buy just one type of fertilizer for your houseplants and outdoor garden, this one does the trick.
If you want to buy just one type of fertilizer for your houseplants and outdoor garden, this one does the trick.
- It’s easy to overfeed with granule fertilizers, so follow the instructions carefully.
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 contains 4% nitrogen, 6% phosphorus, and 5% potassium. 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.
Keep in mind that granulated fertilizer can be very easy to over-apply, so be extra cautious not to feed your potted plants too much or too often. Follow the instructions closely to avoid damaging your indoor plants.
Product Details: Type: Granule | Nutrient Levels: 4-6-5 | Organic or Synthetic: Organic | Application Frequency: Once a month | Quantity: 64 ounces
Best for Flowering Plants
EarthPods Fertilizer Spikes
- These plant fertilizer capsules are completely mess free; simply place them in the soil and let them dissolve slowly.
These plant fertilizer capsules are completely mess free; simply place them in the soil and let them dissolve slowly.
- 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.
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
- This fertilizer contains fungi to help break nutrients down and improve your soil’s quality.
This fertilizer contains fungi to help break nutrients down and improve your soil’s quality.
- It has a strong lingering smell after applying.
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 proprietary 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 users 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 pounds
Best for Cacti and Succulents
The Grow Co Succulent and Cacti Plant Food
- It’s a highly low-maintenance fertilizer—each application should last for up to nine months.
It’s a highly low-maintenance fertilizer—each application should last for up to nine months.
- Pots deeper than four inches will require more pellets.
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 and 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.
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.
It contains 1% nitrogen, 1% phosphorus, and 1% potassium to help your plants store energy and get them growing and flowering. The gentle formula is urea-free to prevent burnt roots, while the magnesium promotes vibrant color and a shiny appearance.
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