10 Best Fish Fertilizer For Plants 2025 in the United States

Neptune's Harvest Fish & Seaweed Fertilizer 2-3-1 is a liquid fertilizer that combines fish and seaweed to provide essential nutrients for plant growth. The NPK ratio of 2-3-1 means it has 2% nitrogen, 3% phosphorus, and 1% potassium, which supports balanced plant growth, flowering, and root development. Its liquid form makes it easy to mix and apply using various methods such as hand watering, sprayers, or drip lines, making it versatile for different gardening needs.

The GS Plant Foods OMRI Listed Fish & Kelp Fertilizer is an organic liquid fertilizer that combines fish and seaweed to promote plant growth. Its NPK ratio, while not explicitly stated, likely balances nutrients from both fish and kelp sources. The fertilizer is in liquid form, making it easy to mix with water and apply to various plants, including vegetables, trees, lawns, shrubs, and flowers.

Neptune's Harvest Fish Fertilizer is a liquid organic fertilizer with an NPK ratio of 2-4-1, providing a balanced mix of nitrogen, phosphorus, and potassium to support healthy plant growth. It is made from fresh North Atlantic fish through a cold process that preserves important nutrients including vitamins, amino acids, enzymes, and growth hormones beneficial to plants. A notable feature is that it retains fish proteins and oils, unlike typical fish emulsions, resulting in a fertilizer with little to no unpleasant fishy odor, making it more user-friendly for home gardeners.