Comparison: Best Fish Fertilizer For Houseplants (Updated | Dec 1st)
But with so many options out there, how do you know which one’s best? In this guide, we’ll compare top-rated fish fertilizers, weighing smell, nutrient content, ease of use, and real results—so you can feed your plants with confidence and watch them flourish.
- Best for vitamin-rich organic: CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer
- Best for bloom-boosting blend: Neptune’s Harvest Fish & Seaweed Fertilizer 2-3-1
- Best for omri certified: Alaska Fish Fertilizer OMRI Listed 5-1-1
- Best for miracle ratio: Indoor Plant Food | All-purpose House Plant Fertilizer | Liquid Common Houseplant Fertilizers for Potted Planting Soil | by Aquatic Arts
- Best for dual-use formula: Monterey Fish & Grow 9-6-2 Fertilizer – 1 Quart Liquid Plant Food for Houseplants
- Best for odorless cold-press: Neptune’s Harvest Fish Fertilizer 2-4-1
- Best for authentic aroma: 1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants
- Best for fish-kelp boost: GS Plant Foods Liquid Fish & Kelp Fertilizer (1 Gallon) – Organic Material Review Institute Listed Natural Plant Food for Home Gardens
- Best for aquarium leaf boost: API LEAF ZONE Freshwater Aquarium Plant Fertilizer 18-Ounce Bottle White
- Best for deep green: Fertilome (10612) Fish Emulsion Fertilizer 5-1-1 (32 oz)
Product Comparison: Best Fish Fertilizer For Houseplants
CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer, 1 Quart
- Promotes healthy plant growth with 11 vitamins
- Can be used on all indoor and outdoor plants
- 100-percent organic
- Stimulates microorganisms
- Does not burn
Neptune’s Harvest Fish & Seaweed Fertilizer 2-3-1, 18 Ounce
- Grow a beautiful vegetable garden
- Flowers and foliage will be stronger and more colorful
- Blooms will be more plentiful, fragrant and longer lasting
- Easy to mix and apply by hand, sprayer, or drip line
Alaska Fish Fertilizer OMRI Listed 5-1-1, 115 oz
- Fish-based fertilizer for use in vegetable, fruit, and flower gardens
- Excellent for use on flowers, trees, and other plants
- OMRI listed
- For organic gardening
- Great for all indoor and outdoor plants
- NPK 5-1-1 fish emulsion fertilizer
- Fish has been used as a natural source of plant nutrients for centuries
- Easy to use, just mix with water
Indoor Plant Food | All-purpose House Plant Fertilizer | Liquid Common Houseplant Fertilizers for Potted Planting Soil | by Aquatic Arts
- FEED HOUSE PLANTS: liquid fertilizer promotes healthy growth and stops wilt better than granules or pellets. Our 3-1-2 Miracle ratio makes living indoor plants thrive in pots, holders, and hangers.
- GROW REAL HOME DECOR: 1 teaspoon for every 2 cups of water includes nitrogen, phosphorus and other vitamins to boost root and bloom growth — easy plant pot growing for up to 1 year.
- Poinsettia, Pothos, Spider Plant, ZZ Plant, Aglaonema, Dioon, Fittonia, Jade Plant, Hoya Plant, Plumeria Plants, Yucca Plant, Hostas, Heuchera Plants, Dracaena Plant, Azalea, Orchid, Snake Plant
- Peace Lily, Begonia, African Violet, Aloe Vera Plant, Weeping Fig, Calla Lillies, Prayer Plant, Philodendron Plant, Dieffenbachia, Croton Plant, Christmas Cactus, Air Plants, Indoor Cactus, Mums
- Rubber Plant, Anthurium, Areca Palm, Lady Palm, Cyclamen, Peacock Plant, Dendrobium, Deacaena, Kalanchoe, Syngonium, Oakleaf Ivy, Aspargus Fern, Bamboo Palm, Boston Fern, Gerbera Daisy, Kimberley
Monterey Fish & Grow 9-6-2 Fertilizer – 1 Quart Liquid Plant Food for Houseplants, Trees, Vegetables & Ornamentals Bundled with Garden Measure Spoon – Covers Up to 4,000 Sq. Ft.
- ALL-PURPOSE LIQUID FERTILIZER – Formulated with fish solubles and nutrients to support strong growth in vegetables, flowers, trees, shrubs, and houseplants.
- DUAL APPLICATION METHODS – Can be used as a foliar spray or soil drench, offering flexible feeding options for indoor or outdoor gardens.
- BALANCED 9-6-2 NPK FORMULA – Delivers essential nutrients including nitrogen, phosphate, and potassium for vibrant, lush plant development.
- EASY TO MIX AND APPLY – Simply mix ½ oz per gallon of water; suitable for hose-end sprayers or watering cans; shake well before use.
- COVERS UP TO 4,000 SQ FT – One quart provides ample coverage for large garden areas, with monthly or bi-weekly use during the growing season.
Neptune’s Harvest Fish Fertilizer 2-4-1, 18 Ounce
- Neptune’s Harvest is an organic fertilizer made from fresh north Atlantic fish
- It is made by a unique cold process that protects the vitamins, amino acids, enzymes and growth hormones
- It also contains all the micro and macro nutrients naturally found in fish
- Unlike fish emulsions, Neptune’s Harvest retains the fish proteins and oils and has no unpleasant odor
1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants, Flowers, Fruits & Vegetables, 2-3-1 NPK – Sustainably Sourced and Hydrolyzed for Steady Growth
- ORGANIC FISH EMULSION FERTILIZER – Our liquid fish fertilizer is made from sustainably sourced fish emulsion and we use up all the parts that would otherwise go to waste. Using an environmentally conscious method, ingredients are refined fresh and 100% cold pressed to help retain all of the nutrients, vitamins, and amino acids needed to grow healthy plants.
- GROW PLANTS NATURALLY – This wonderfully organic alternative to synthetic fertilizer contains a 2-3-1 NPK ratio perfect for light and frequent applications. Promotes steady, healthy plant development throughout the growing season.
- ENRICHES SOIL – Helps build a strong foundation for your organic garden to thrive on! Use as an effective soil drench to improve fertility, structure, and encourage the growth of beneficial microorganisms like fungi in your garden’s soil.
- PRODUCE MORE – Get the most out of your fertilizer and your garden! This organic garden fertilizer helps to increase crop yields and flower blooms. Gentle enough to use as a foliar spray makes this the perfect fish fertilizer for plants, flowers, and vegetables.
- SMELL THE DIFFERENCE – This fertilizer smells like fish because it’s made from fish! Crafted with high-quality concentrated and undiluted hydrolyzed fish emulsion each bottle gives off a pungent fishy aroma. When compared, we see it like this – if it doesn’t smell, then it’s not real fish!
GS Plant Foods Liquid Fish & Kelp Fertilizer (1 Gallon) – Organic Material Review Institute Listed Natural Plant Food for Home Gardens, Lawns, and Vegetables
- ORGANIC MATERIALS REVIEW INSTITUTE LISTED FOR TRUSTED GARDEN CARE Certified by OMRI for use in organic growing, GS Plant Foods Liquid Fish & Kelp Fertilizer delivers reliable, natural nutrition for vegetables, lawns, flowers, and shrubs.
- SEA-AND-SOIL BASED NUTRITION Made from North Atlantic seaweed (Ascophyllum nodosum) and fresh fish hydrolysate, this liquid concentrate provides essential nutrients and trace minerals that help support healthy soil and plant development.
- IMPROVES SOIL MICROBIOLOGY & NUTRIENT UPTAKE Supports a thriving soil ecosystem that promotes strong root systems and efficient nutrient absorption — the foundation for resilient, productive plants.
- EASY-TO-USE CONCENTRATE FOR ALL PLANTS Mix 2 oz per gallon of water and apply as a foliar spray or soil drench every 2–4 weeks. Safe for use on vegetables, fruits, ornamentals, turf, and houseplants.
- MADE IN THE USA – SUSTAINABLY PRODUCED Proudly produced by GS Plant Foods as a licensed fertilizer manufacturer. No synthetic chemicals, additives, or fillers — just natural ingredients formulated for healthy home gardens and hobby farms.
API LEAF ZONE Freshwater Aquarium Plant Fertilizer 18-Ounce Bottle White
- Contains one (1) API LEAF ZONE Freshwater Aquarium Plant Fertilizer 16-Ounce Bottle
- Promotes strong, hardy and colorful leaves and prevents yellow, decaying leaves
- Contains essential nutrients including chelated iron and potassium
- Formulated for rapid absorption in freshwater aquarium plants
- Dose your aquarium weekly with 5 ml of API LEAF ZONE per 10 US gallons of aquarium water
Fertilome (10612) Fish Emulsion Fertilizer 5-1-1 (32 oz)
- Develops deep green foliage, vigorous root systems and a solid plant structure
- Derived from fish soluble, can be used from indoor and outdoor. Can be used on plants and trees.
- Mixes with water and can be used by any convenient method of application. Shake well before use.
- 5-1-1 Fertilizer contains 5% Nitrogen, 1% Phosphate and 1% Soluble Potash.
- For plants mix 1-2 tbsp per 1 gal of water. For trees mix 4 tbsp per gal of water.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Buying Guide
FAQs
What should I look for when choosing a fish fertilizer for houseplants?
Focus on the NPK ratio, as a balanced formula like 2-3-1 or 3-1-2 supports steady growth without over-fertilizing. Check if the product is OMRI‑listed or certified organic, which ensures it meets organic gardening standards. Also consider the concentration and recommended dilution rate to match your watering routine.
How does a liquid fish emulsion compare to a granule or pellet fertilizer for indoor plants?
Liquid emulsions dissolve quickly, delivering nutrients directly to the root zone and allowing precise dosing each watering. Granules release nutrients more slowly, which can be beneficial for long‑term feeding but may be harder to control indoors. For most houseplants, a liquid formula offers faster results and less risk of buildup on potting mix.
Is a higher NPK ratio always better for houseplants?
Not necessarily; houseplants generally need lower nitrogen to avoid excessive foliage at the expense of root health. Ratios like 2-3-1 or 3-1-2 provide a gentle nitrogen boost while emphasizing phosphorus for root development and potassium for overall vigor. Choose a formula that matches the specific growth stage of your plants.
What are the benefits of fish fertilizers that include seaweed or kelp?
Seaweed adds trace minerals, hormones, and natural growth enhancers that improve stress tolerance and leaf coloration. Products such as GS Plant Foods’ fish & kelp blend also support soil microbiology, helping beneficial microbes break down nutrients. This combination can lead to healthier, more resilient indoor plants.
How important is the odor of a fish fertilizer for indoor use?
While a mild fishy smell is normal, strong odors can be unpleasant in a home environment. Some brands use cold‑process methods that reduce odor, like Neptune’s Harvest, making them more suitable for indoor spaces. If scent is a concern, look for products marketed as low‑odor or that recommend diluting before application.
Which fish fertilizer offers the best value for larger indoor gardens?
The 1‑gallon options, such as the Organic Fish Emulsion (1 Gallon) and GS Plant Foods Liquid Fish & Kelp (1 Gallon), provide a lower cost per ounce and cover extensive planting areas. Their higher volume also means fewer repurchases throughout the growing season. For smaller collections of houseplants, a quart‑size bottle may be more convenient and less wasteful.
Can I use the same fish fertilizer on both houseplants and outdoor garden plants?
Many fish emulsions are formulated for universal use, including indoor and outdoor applications, as noted on products like Central Garden Brands and Alaska Fish Fertilizer. However, outdoor plants may benefit from higher application rates due to larger soil volumes. Always follow the label’s dilution guidelines for each environment.
What extra features should I consider beyond the basic nutrient content?
Look for added vitamins, amino acids, or microbial stimulants that promote soil health, as highlighted by Central Garden Brands’ 11‑vitamin blend. Certifications such as OMRI listing assure compliance with organic standards, which can be important for eco‑conscious gardeners. Finally, ease of mixing—whether the product can be applied with a sprayer, watering can, or hose‑end sprayer—can simplify regular feeding.