Fish Fertilizer
Liquid fish fertilizer that feeds plants and soil life with naturally derived nutrition. Rich, gentle fish plant food for gardens and houseplants.
The liquid formula fits into regular watering, making consistent feeding easy for everyday plant care.
Why You'll Love It
- Organic Nutrition Nitrogen-forward feeding made from fish protein hydrolysate, not synthetic salts.
- Steady Growth For pale, slow growth on hungry plants early in the season.
- Gentle Feeding A gentle organic feed that won't burn what you put it on.
Made by growers
More than a bottle on a shelf.
- Talk to real plant people. The team that mixes the formula answers your email.
- Made in-house, in the USA. Every bottle mixed and filled by us, not a third party.
- We're growers, not resellers. We use this on our own plants before it ships.
- Bundle savings only here. Pair any two TPS formulas — your order ships free.
Fish Fertilizer with a nitrogen-forward 4-2-0.4 NPK, made from fish protein hydrolysate — a gentle organic feed for all kinds of plants that supports steady green growth without the burn risk of harsh synthetics. The nitrogen lead drives leafy growth and overall vigor, while the fish-protein base feeds soil life along with the plant, the way traditional fish emulsions have for generations.
How to Use Fish Fertilizer
| Method | Amount | How Often |
|---|---|---|
| Watering can | 2 to 4 Tbs per gallon of water | Spring & Summer: every 1-2 weeks |
| Watering can | Same dilution | Fall & Winter: every 4 weeks |
| Hose-end sprayer | Set dial to 2 oz (60mL) setting | Spring & Summer: every 1-2 weeks |
Mix into your normal watering — no separate feeding routine needed. It's fish-based, so expect a natural odor for a short while after applying.
What's Inside
The 4-2-0.4 ratio leads with nitrogen because this is built as a general growth feed — the 4% nitrogen drives the leafy, green growth most plants want through the season, backed by 2% phosphate for roots and a small amount of potash. The nitrogen comes as 3% ammoniacal and 1% other water-soluble nitrogen from fish protein hydrolysate, which releases gently as it breaks down, so it feeds steadily and is very forgiving — hard to burn plants with, even at the higher end of the rate.
Beyond NPK: this is a fish-protein fertilizer rather than a mineral blend, so its value is in the organic nitrogen and the way fish hydrolysate feeds soil microbes alongside the plant, building healthier soil over time. Phosphoric acid is included to stabilize the pH of the liquid. Because it's nitrogen-forward and light on phosphorus and potassium, it's best as an all-purpose growth feed; for heavy flowering or fruiting, pair it with a higher phosphorus and potassium product during bloom.
Made For
Built as an all-purpose feed for nearly any plant — vegetables, leafy greens, lawns, annuals, houseplants, and young transplants — anywhere a gentle, nitrogen-forward organic fertilizer suits, indoors or out.
Problems It Solves
- Pale, slow growth on hungry plants
- Weak leafy growth early in the season
- Wanting a gentle organic feed that won't burn
- Tired soil that needs feeding along with the plant
FAQs
How often should I use fish fertilizer?
During spring and summer, feed every 1-2 weeks with 2 to 4 Tbsp per gallon in a watering can, or use the hose-end sprayer on the 2 oz setting. In fall and winter, cut back to once every 4 weeks. Start at the lower 2 Tbsp rate for tender or young plants and move toward 4 Tbsp for hungry, fast-growing crops. Because it's a gentle organic feed, it's forgiving, but there's no benefit to exceeding the labeled rate.
Does fish fertilizer smell bad?
It has a natural fishy odor when applied, since it's made from fish protein — that's normal and fades within a day or two outdoors as it soaks in. For indoor plants, the smell is more noticeable in an enclosed space, so many people use it on houseplants sparingly or water them in a sink or tub and let them air out. Watering it in well and not overapplying keeps the odor brief. The smell isn't a sign of a problem.
Is fish fertilizer good for vegetables?
Yes — it's a classic choice for vegetable gardens, especially leafy crops and young plants that want steady nitrogen for green growth. The gentle organic nitrogen is forgiving and feeds the soil as well as the plant. For fruiting crops like tomatoes and peppers, it's a good early-season growth feed, but as they start flowering you may want to add a higher phosphorus and potassium fertilizer, since this blend is light on both.
Can I use fish fertilizer on houseplants?
You can, at the lower end of the rate, but the smell is the main consideration indoors. If you use it on houseplants, water it in well and expect a temporary odor, or move the plants to a sink or outdoors to feed and air out. The gentle, low-burn nature suits potted plants, but many indoor growers prefer it for outdoor use and choose a low-odor fertilizer for plants that live in living spaces.
When will I see results?
Plants usually green up and show fresh growth within one to two weeks during the growing season, as the nitrogen becomes available. Organic fish fertilizer releases a little more gradually than a synthetic, so the response is steady rather than sudden, and it builds soil health over repeated feedings. The clearest results come from consistent feeding across the season rather than a single application.
Related Products
Fish Emulsion Fertilizer Seaweed Fertilizer All Purpose Fertilizer