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How to Use Liquid Fish Fertilizer

Liquid fish fertilizer is available in garden centers and online, and it comes in various types for different applications. Some liquid fish fertilizer is blended with kelp, some is processed from specific fish (for example salmon), and some is made to be applied only as a foliar spray. Manufacturers include plenty of information on their products to help you select the correct liquid fish fertilizer and to use the correct dilution ratio for your needs.

Feeding Your Plants

Spray lawns with a solution of three tablespoons liquid fish fertilizer per gallon of water. This provides plenty of nitrogen to support good grass blade growth. In a lawn watering system, use liquid fish fertilizer at 1/2 gallon per 1000 square feet of lawn. Beginning when grass greens up in the spring, apply fertilizer to lawns every four weeks during the growing season.

Stand cuttings for rooting or transplanting in a mixture of three tablespoons liquid fish fertilizer per gallon of water. Leave them overnight in the solution for a boost before transplanting. After transplanting, water the transplants with the remaining mixture.

Mix a dilution of three tablespoons liquid fish fertilizer per gallon of water for foliar feeding. Spray it on the leaves and stems of the plants once every two weeks. Some companies sell a pre-diluted foliar feed, so check the package to see if dilution is necessary.

Foliar feeding may be used on any garden plant or houseplant. Use early in the day so the leaves will dry before evening, and avoid spraying during the hottest part of the day.

Use a dilution rate of three tablespoons liquid fish fertilizer per gallon of water in drip irrigation systems in your garden for general watering and feeding of all plants. The same dilution is used for direct soil watering if you use a watering can.

For garden plants that need strong stems, use a blend of liquid fish fertilizer and kelp fertilizer. The blend encourages leaf growth while strengthening stems and aiding in fruit set. Tomatoes and peppers are examples of plants that benefit from this blend.

Improve the nutrient content of your compost pile, and help speed decomposition. Spray your compost pile with three tablespoons liquid fish fertilizer per gallon of water to moisten the pile, and the nutrients will be retained in your finished compost.


Always use manufacturer’s dilution instructions. Liquid fish fertilizers are consistent within each product, but they are not necessarily standardized from one brand to another. Different sources of fish may have different levels of organic compounds, and manufacturers develop their own products accordingly.


Fish Pharm® warns not to use their salmon-based foliar fertilizer in areas where bears live.

Do not use kelp blends on edible plants from which you eat the stems, such as broccoli, kale, lettuce or spinach. It can cause the plants to develop stringy stems.

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