Comparison: Best Plant Fish Fertilizer (Updated | Dec 1st)
One’s packed with natural nutrients from the sea, the other harnesses the power of microbes and organic matter. But which one truly gives your garden the edge? Let’s dive into the benefits, drawbacks, and real results of the best plant and fish fertilizers to help you decide what’s best for your green babies.
- Best for vitamin-rich organic: CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer
- Best for omri certified: Alaska Fish Fertilizer OMRI Listed 5-1-1
- Best for aquarium leaf boost: API LEAF ZONE Freshwater Aquarium Plant Fertilizer 8-Ounce Bottle
- Best for deep green growth: Fertilome (10612) Fish Emulsion Fertilizer 5-1-1 (32 oz)
- Best for cold-processed odorless: Neptune’s Harvest Fish Fertilizer 2-4-1
- Best for wintergreen burn-free: Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon (Packaging may vary)
- Best for salmon nutrient power: Fish Emulsion Fertilizer
- Best for fish-kelp soil boost: GS Plant Foods Liquid Fish & Kelp Fertilizer (1 Gallon) – Organic Material Review Institute Listed Natural Plant Food for Home Gardens
- Best for cold-pressed yield: 1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants
- Best for root development tabs: API ROOT TABS Freshwater Aquarium Plant Fertilizer 0.4-Ounce 10-Count Box
Product Comparison: Best Plant Fish Fertilizer
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
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
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.
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
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
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!
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
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 a fish fertilizer for my garden?
The most important components are a balanced N-P-K ratio, usually around 2-3-1 or 5-1-1, and the presence of micronutrients like iron and trace minerals. Look for products that also contain organic matter such as fish proteins, oils, and kelp, which improve soil structure and support beneficial microbes.
How does the N‑P‑K ratio affect plant growth, and which ratio is best for vegetables versus ornamental plants?
Higher nitrogen (the first number) promotes leafy growth, making a 5‑1‑1 ratio ideal for fast‑growing vegetables and lawns. A lower nitrogen, higher potassium ratio such as 2‑4‑1 supports flower and fruit development, which is better for ornamental plants and fruit‑bearing crops.
Are OMRI‑listed fish fertilizers worth the extra cost?
OMRI‑listed products, like the Alaska Fish Fertilizer, guarantee compliance with organic certification standards, which is important for certified organic growers. While they may be slightly pricier, the assurance of no synthetic additives and the added market value for organic produce can justify the expense.
Which fish fertilizer has the least odor and is suitable for indoor use?
Neptune’s Harvest and Alaska Fish Emulsion both use deodorizing processes; Neptune’s Harvest retains fish proteins without a strong smell, and Alaska’s version is wintergreen‑deodorized. These formulations are safe for indoor plants and reduce the risk of lingering fishy odors in your home.
How do liquid fish fertilizers compare to tablet or root‑tab formats for aquarium plants?
Liquid fertilizers, such as API Leaf Zone, allow precise dosing and quick nutrient uptake, making them ideal for regular water changes. Tablet formats like API Root Tabs provide a slow‑release source directly at the root zone, which can be more convenient for long‑term maintenance but may require periodic replacement.
What is the best way to apply a concentrated fish emulsion to a large garden?
Dilute the concentrate according to the label—typically 1‑2 tablespoons per gallon of water for garden beds and up to 4 tablespoons per gallon for trees. Apply the solution as a soil drench or foliar spray every 2‑4 weeks, ensuring even coverage for consistent nutrient absorption.
Is it more cost‑effective to buy a larger container of fish fertilizer, or does a smaller bottle offer better value?
Larger containers, like the 1‑gallon GS Plant Foods or 5‑gallon Alaska Fish Emulsion, usually have a lower cost per ounce and are best for extensive planting areas. However, if you only have a few indoor pots or a small balcony garden, a 8‑oz bottle provides enough product without waste, making it a better value for limited use.