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Fish Emulsion for Plants

By Brian Hill ; Updated September 21, 2017
Organic fertilizer contributes to plant health.
green vegetables image by Steve Lovegrove from Fotolia.com

Fish emulsion is an organic liquid fertilizer beneficial for many different kinds of plants. The value of fish emulsion is that nutrients are delivered to the plant right away, providing a kind of quick energy boost. Other types of organic fertilizers release nutrients much more slowly. Noticeable greening and growth of plants can occur within a few days of application of fish emulsion.

Where It Comes From

Fish emulsion is produced from waste products of the fish oil or fish meal industries. Fish meal is used as animal feed. It is often produced from the small menhaden fish. If not used to produce organic fertilizer, these waste products would be disposed of in landfills.

How It Is Made

In the processing plant, the fish are cooked and then put under pressure so the fish oil is released. The solids are separated to become animal feed. The remaining waste liquids are then cooked down once more and thickened into fish emulsion. A tiny amount of phosphoric acid, less than 1 percent, is put into the mixture to prevent fermentation of the emulsion, which can produce gas after the product is bottled.

What It Contains

The proportions of nutrients vary by brand of fish emulsion, but they are often 5 percent nitrogen, 2 percent phosphorous and 2 percent potassium. Fish emulsion also contains many important micronutrients, chemical elements needed by plants for healthy growth.

Where It Is Used

Fish emulsion can be used on newly transplanted seedlings to give them a healthy start. During the cooler temperatures in spring, applying fish emulsion can provide nutrients to support the onset of rapid spring growth. If plants begin to struggle during the middle of their growing season, it can be used to revitalize them. In addition to be an organic source of nutrients for annual vegetables, perennial flowers, roses, and shrubs, fish emulsion can green up a lawn or accelerate the growth of foliage on trees. Because new formulations of fish emulsion have less odor, it can even be used on indoor plants.

How to Apply It

Fish emulsion is always applied in a heavily diluted form and is either sprayed into the leaves of plants, referred to by gardeners as foliar feeding, or in the case of trees, applied to the soil at the tree’s base. The product’s label provides specific directions on how diluted the mixture should be depending on the plant you are feeding. Apply fish emulsion early in the morning or in the cooler evening hours because under the hot sun the fish odor is more pronounced. After making the fish emulsion and water solution, use it that day. The mixture’s effectiveness declines when stored.


About the Author


Brian Hill is the author of four popular business and finance books: "The Making of a Bestseller," "Inside Secrets to Venture Capital," "Attracting Capital from Angels" and his latest book, published in 2013, "The Pocket Small Business Owner's Guide to Business Plans."