Comparison: Best Fish Fertilizer For Plants Amazon (Updated | Dec 1st)
We’ve dug into the top-rated fish fertilizers on Amazon, checking ingredients, customer reviews, and real garden results. Whether you’re growing tomatoes, roses, or houseplants, we’ll help you pick the perfect formula that feeds your soil and keeps your plants thriving—all without the guesswork.
- Best for vitamin-rich boost: CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer
- Best for omri certified blend: Alaska Fish Fertilizer OMRI Listed 5-1-1
- Best for wintergreen deodorized: Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon (Packaging may vary)
- Best for salmon nutrient power: Fish Emulsion Fertilizer
- Best for root development tabs: API ROOT TABS Freshwater Aquarium Plant Fertilizer 0.4-Ounce 10-Count Box
- Best for leaf zone formula: API LEAF ZONE Freshwater Aquarium Plant Fertilizer 8-Ounce Bottle
- Best for odorless fish fusion: Neptune’s Harvest Fish Fertilizer 2-4-1
- Best for kelp-enhanced soil: GS Plant Foods Liquid Fish & Kelp Fertilizer (1 Gallon) – Organic Material Review Institute Listed Natural Plant Food for Home Gardens
- Best for cold-pressed emulsion: 1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants
- Best for seaweed bloom booster: Neptune’s Harvest Fish & Seaweed Fertilizer 2-3-1
Product Comparison: Best Fish Fertilizer For Plants Amazon
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
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
Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon (Packaging may vary)
- Will Not Burn
- Great for all plants
- Deodorized with Natural Wintergreen
- 5-1-1 fertilizer is an excellent source of organic plant nutrients
- Fish Fertilizer
Fish Emulsion Fertilizer, Complete Fish Emulsion Plant Food, 8 oz (250mL)
- Complete fish fertilizer for thriving plants
- Helps growth with natural harvest salmon nutrients
- Easy-to-follow care instructions included
- Made in the USA
API ROOT TABS Freshwater Aquarium Plant Fertilizer 0.4-Ounce 10-Count Box
- Contains one (1) API ROOT TABS Freshwater Aquarium Plant Fertilizer 0. 4-Ounce 10-Count Box
- Promotes strong root development for lush plants in freshwater aquariums
- Contains essential nutrients including iron, potassium and carbon
- Helps new aquatic plants get off to a vigorous start and to keep established plants flourishing
- Add tablets to gravel bed every month to ensure best results
API LEAF ZONE Freshwater Aquarium Plant Fertilizer 8-Ounce Bottle
- Product Type: ARTIFICIAL PLANT
- Package length: 19.558 cm
- Package width: 3.048 cm
- Package height: 4.572 cm
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
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.
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!
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
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 my garden?
First check the NPK ratio; a 2-3-1 or 5-1-1 blend provides balanced nitrogen for leaf growth and phosphorus for root development. Look for OMRI‑listed products if you practice organic gardening, and consider whether the formula is liquid, concentrate, or tablet based on your preferred application method.
How do liquid fish emulsions compare to tablet‑type fertilizers?
Liquid emulsions, such as the Central Garden Brands 1‑quart or GS Plant Foods 1‑gallon, dissolve quickly and can be used as a soil drench or foliar spray for fast nutrient uptake. Tablet products like API ROOT TABS are convenient for aquarium plants and release nutrients slowly, but they may not provide enough nitrogen for larger outdoor beds.
Is odor a problem with fish fertilizers, and which products minimize it?
Many fish emulsions have a noticeable scent, but brands like Alaska Fish Emulsion 5‑1‑1 are deodorized with natural wintergreen to reduce the smell. If odor is a major concern, consider using a cold‑processed formula like Neptune’s Harvest, which retains nutrients while having a milder aroma.
Why is an OMRI listing important, and which items have it?
OMRI (Organic Materials Review Institute) certification guarantees the product meets organic standards, making it safe for certified organic farms and gardens. Alaska Fish Fertilizer 5‑1‑1, GS Plant Foods Liquid Fish & Kelp, and the 1‑gallon Organic Fish Emulsion all carry the OMRI label.
How do I evaluate value for money across different sizes?
Calculate the cost per ounce; larger containers like the 1‑gallon GS Plant Foods (≈128 oz) or the 1‑gallon Organic Fish Emulsion typically offer a lower price per ounce than 8‑oz bottles. However, factor in concentration—some 1‑gallon formulas require dilution, which can stretch the product even further.
Can I use the same fish fertilizer for indoor houseplants and outdoor gardens?
Yes, most fish emulsions are safe for both indoor and outdoor use, including Central Garden Brands and Alaska Fish Emulsion. Just ensure proper ventilation when applying indoors and follow dilution guidelines to avoid over‑fertilizing.
What extra benefits do kelp or seaweed additives provide?
Kelp‑based ingredients, like those in GS Plant Foods, supply trace minerals, hormones, and micronutrients that improve soil microbiology and boost plant stress tolerance. This can lead to stronger root systems and more vibrant foliage compared with pure fish emulsion alone.
How should I apply fish fertilizer for the best results?
Mix liquid concentrates according to the label—usually 2 oz per gallon of water—and apply as a soil drench every 2–4 weeks, or use a foliar spray for quick leaf uptake. Tablet products are placed in the planting substrate or added to the aquarium gravel, while larger containers can also be applied via drip irrigation for larger beds.