Comparison: Best Organic Fish Fertilizer For Plants (Updated | Dec 1st)
We’ve done the messy work—sniff-testing bottles, digging into ingredients, and watching real plants respond—so you don’t have to. Whether you’re growing tomatoes, flowers, or houseplants, we’ll help you find the right fish-based feed that’s effective, eco-friendly, and easy to use.
- Best for vitamin-rich boost: CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer
- Best for high npk power: 1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants
- Best for omri certified 5-1-1: Alaska Fish Fertilizer OMRI Listed 5-1-1
- Best for macro-micro fusion: GS Plant Foods Organic Liquid Fish Fertilizer – Natures Growth Boost
- Best for fish & kelp blend: GS Plant Foods Liquid Fish & Kelp Fertilizer (1 Gallon) – Organic Material Review Institute Listed Natural Plant Food for Home Gardens
- Best for balanced 7-7-2: Down To Earth All Natural Fertilizers Organic Bio-Fish – Plant Food for Corn
- Best for salmon omega boost: Bloom City Organic Wild Fish Fertilizer and Plant Supplement
- Best for root-boost bone meal: Down To Earth All Natural Fertilizers Organic Fish Bone Meal – High Phosphorus Plant Food for Buds
- Best for fast-acting liquid: Down To Earth All Natural Fertilizers Organic Liquid Fish & Kelp Concentrate – Plant Food for Vegetable Gardens and Flower Beds – Makes up to 32 Gallons 2-4-1
- Best for odorless protein rich: Neptune’s Harvest Fish Fertilizer 2-4-1
Product Comparison: Best Organic Fish Fertilizer For Plants
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
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!
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
GS Plant Foods Organic Liquid Fish Fertilizer – Natures Growth Boost, OMRI-Certified, Hydrolyzed, Fish-Based, Organic Gardening Solution, 1 Quart
- OMRI ORGANIC LISTED HYDROLYZED FISH FERTILIZER: GS Plant Foods Organic Liquid Fish is an all-natural high quality fresh fish liquid fertilizer that gives excellent plant growth, rebuilds soil, and offers higher production yields. Our fish fertilizer will help stimulate growth and improve plant health and color. Tremendously beneficial for soil quality and improved rooting, this organic fish fertilizer can be applied to any type of soil or plant without concern for waste or harmful chemicals.
- PACKED WITH MACRO & MICRO NUTRIENTS: Our proprietary and all-natural fish fertilizer provides much more than N-P-K (Nitrogen, Phosphorus and Potassium) found in synthetic fertilizers. This fish plant fertilizer provides a comprehensive mix of macro & micro nutrients, minerals, peptides, proteins, and calcium, all in a usable form perfectly suited for maximum efficiency of uptake for your plants. The fish plant food fertilizer stimulates water penetration and increases nutrient assimilation.
- OPTIMAL PLANT GROWTH & HEALTH AT HOME OR COMMERCIALLY: Used in low concentrations, liquid fish fertilizer organic acts as an efficacious growth promoter. GS Plant Foods organic hydrolyzed fertilizer promotes growth of healthy bacteria. It is used extensively on a commercial basis, as well as at home as an organic soil conditioner. The end result is a powerfully effective, organic fertilizer and soil supplement that contains no chlorine or heavy metals. It is great for everything that grows!
- WORKS SYNERGISTICALLY WITH ALL FERTILIZERS:This liquid fish fertilizer is among the highest quality plant food products that you can get. It works synergistically with all fertilizers especially with a high quality liquid kelp fertilizer such as GS Plant Foods Organic Liquid Kelp. Use fish fertilizer on lawns, vegetables, fruits, trees & shrubs, seedlings and transplants as a regular healthful maintenance program to experience healthier plants with stronger, and more developed root systems.
- EASY TO APPLY FOR NATURAL GREAT RESULTS: Apply hydrolyzed fish fertilizer to improve specific growth stages. Apply generously to soil or as a foliar feed until leaves are wet, top and bottom. For lawns, one gallon of fertilizer mixed with 30-40 gallons of water will cover ¼ acre. Feed lawn every 4 weeks. Trees and shrubs use 4 oz per gallon of water. Feed by boring small holes 1 to 2 feet away from the root ball. Fill holes with solution. For best results, foliar feed early or late in the day.
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.
Down To Earth All Natural Fertilizers Organic Bio-Fish – Plant Food for Corn, Broccoli, Kale, Trees and Shrubs 7-7-2, 5 lb
- Balanced NPK Formula (7-7-2): Provides equal parts nitrogen and phosphorus for robust vegetative growth and root development, plus potassium for improved resilience and bloom support.
- Marine-Based Fertility Boost: Made with fish meal and fish bone meal—ideal for improving soil biology and long-term fertility.
- OMRI Listed for Organic Use: Safe and approved for certified organic farming and gardening systems.
- Feeds Soil & Plants Naturally: Encourages beneficial microbial activity, resulting in better nutrient absorption and stronger plants.
- Great for Vegetables, Fruits & Flowers: Versatile enough for raised beds, garden rows, containers, and landscape use.
Bloom City Organic Wild Fish Fertilizer and Plant Supplement, Great for Roots and Soil, Made from Sustainable Salmon, Quart (32 oz)
- FROM SUSTAINABLE ALASKAN SALMON: Great for Soil and Plants, for indoor and outdoor use.
- CONTAINS SALMON EMULSION AND SALMON OIL: Very high in omega 3 Fatty Acids for Plants. More Amino Acids than any other brand.
- SMELLS LIKE FISH: You know this is the good stuff, because is really really smells like ocean and fish.
- HIGHEST QUALITY, MOST POTENT, BEST VALUE, BIGGEST YIELD: Bloom City’s ingredients are better for plants, better for you, and better for the planet. Simply the best choice for the conscientious grower.
- FORMULATED AND MADE IN THE USA: Designed by botanists and plant chemists in Seattle, Washington. Bloom City chooses only the highest quality ingredient sources and manufacturing methods to create the world’s best craft growing nutrient systems.
Down To Earth All Natural Fertilizers Organic Fish Bone Meal – High Phosphorus Plant Food for Buds, Bulbs, Blooms, Flower Beds 4-12-0, 5 lb
- Water-Soluble Formula – Easily dissolves in water for quick absorption and efficient nutrient delivery directly to the root zone
- Targets Root Development – Formulated to enhance root growth, improving plant stability, nutrient uptake, and drought resistance
- Fast-Acting Nutrients – Provides immediate access to essential nutrients like nitrogen, phosphorus, and potassium where roots need them most.
- Ideal for Transplants & Seedlings – Great for jumpstarting young plants or helping transplants establish quickly in new soil.
- Improves Soil-Root Interaction – Encourages a healthy rhizosphere, boosting microbial activity and root-zone nutrient cycling.
Down To Earth All Natural Fertilizers Organic Liquid Fish & Kelp Concentrate – Plant Food for Vegetable Gardens and Flower Beds – Makes up to 32 Gallons 2-4-1, 32 oz
- Fast‑acting liquid formula: Perfect for foliar feed or soil drench applications, supporting quick absorption and growth stimulation.
- Stimulates overall plant vigor: High phosphorus aids flowering and fruiting, while nitrogen supports lush foliage and root development.
- Organic & soil‑friendly: Helps promote beneficial microbial activity and sustainable soil health due to its fish and kelp base
- Versatile application rates: For general garden use: ¼–½ cup per gallon of water; for containers: 2–4 Tbsp per gallon; for houseplants: 2 Tbsp per gallon, repeated every 2–4 weeks depending on growth stage
- Watch out for odor: While extremely effective, many users report a strong fish-like odor characteristic of fish emulsions—though it typically subsides quickly and doesn’t linger long indoors
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
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 key ingredients should I look for in an organic fish fertilizer?
The most important ingredients are hydrolyzed fish emulsion, fish meal, or fish bone meal, which provide nitrogen, phosphorus, and trace minerals. Look for products that also list added micronutrients like calcium, iron, and amino acids, as these support overall plant health. An OMRI listing indicates the fertilizer meets organic standards.
How does the NPK ratio affect plant growth when choosing a fish fertilizer?
A lower NPK ratio such as 2-3-1 or 5-1-1 promotes balanced vegetative growth and encourages strong root development without causing excess leaf growth. Higher nitrogen ratios can boost foliage but may reduce flowering, while higher phosphorus supports blooms and fruit set. Choose a ratio that matches the growth stage of your plants.
Is a larger container (gallon) more cost‑effective than a quart of fish fertilizer?
Generally, buying in bulk reduces the price per ounce, making a gallon a better value for frequent users. However, consider how quickly you will use the product; fish emulsions can lose potency over time if not stored properly. If you have a small garden or occasional use, a quart may be more practical despite the higher unit cost.
Do fish fertilizers differ in odor, and does that matter?
All true fish emulsions have a noticeable fishy smell because they contain real fish proteins and oils; a strong odor often signals authenticity. Some brands use processing methods that reduce the smell, but the scent does not affect nutrient content. If indoor use is a concern, choose a formula marketed as low‑odor or apply it outdoors.
How important is OMRI certification when comparing fish fertilizers?
OMRI certification guarantees the product complies with organic farming regulations, which is essential for certified organic growers. It also reassures consumers that the fertilizer contains no synthetic chemicals or prohibited additives. While non‑OMRI products can still be effective, the label adds confidence for organic gardening.
Can I mix fish fertilizer with other organic amendments like kelp or compost?
Yes, fish fertilizer works synergistically with kelp extracts, compost teas, and other organic amendments, enhancing nutrient uptake and soil microbiology. Mixing them can provide a broader spectrum of macro and micronutrients and improve soil structure. Follow label dilution rates to avoid over‑feeding and maintain balanced nutrition.
What application methods give the best results for fish fertilizers?
Both soil drenching and foliar feeding are effective; soil drench delivers nutrients directly to the root zone, while foliar spray provides a quick nutrient boost to leaves. For larger areas, dilute the fertilizer according to the manufacturer’s instructions and apply with a watering can or hose-end sprayer. Re‑apply every 2–4 weeks during the growing season for consistent growth.
How do I evaluate the overall value of a fish fertilizer beyond price?
Consider the concentration of nutrients, the presence of additional micronutrients, and the product’s shelf life. A higher‑concentration formula may require less frequent applications, saving time and labor. Also factor in certifications, odor control, and any bundled benefits such as improved soil microbiology, which can enhance long‑term garden productivity.