10 Best Kelp For Garden 2025 in the United States

GS Plant Foods Fish & Kelp Fertilizer is a liquid blend combining hydrolyzed fish and seaweed, making it rich in natural nutrients that support plant growth and soil health. Being OMRI listed means it meets organic standards, appealing to gardeners wanting an organic option free from harmful runoff. The liquid form allows easy mixing with water, and the product provides flexible use across a wide range of plants including vegetables, trees, flowers, and lawns.

Application instructions are straightforward, with different dilution rates for indoor plants, outdoor plants, and lawns, making it adaptable for various garden needs. Its nutrient content, coming from both fish and kelp, supplies not only nitrogen but also trace minerals and growth-promoting compounds typical of seaweed, helping plants grow stronger and healthier. The product is made in the USA, and the brand emphasizes quality and sustainability, adding trustworthiness.

Since it is a liquid with a fish base, some users might notice an odor during application, and it requires regular feeding every 2-3 weeks to maintain benefits. Also, while compatible with many fertilizers, it’s best to follow guidelines to avoid overfeeding. This fertilizer is well suited for gardeners seeking an organic, multipurpose soil enhancer that supports steady growth, especially in home gardens and small commercial setups.

The Bloom City Organic Liquid Seaweed and Kelp Fertilizer Supplement is a versatile and user-friendly product designed for garden enthusiasts. It comes in a concentrated liquid form, making it easy to mix and apply. The product is fully organic, featuring a seven-species blend of kelp, which includes Ascophyllum Nodosum, Palmaria Palmata, and others. This blend ensures a rich nutrient content beneficial for various stages of plant growth, from roots to stems. Its unique extraction process retains the natural enzymes and hormones, providing a cleaner and more effective kelp extract without the non-nutritious pulp found in other products. This makes the liquid clear and easy to handle, avoiding the thick, brackish appearance typical of other kelps.

The fertilizer is formulated in the USA by botanists and plant chemists, ensuring high-quality and reliable performance. It's simple and safe to use for all plants and lawns, with clear application instructions that recommend adding the product to every watering. This ease of use, combined with the absence of over-application risk, makes it suitable for both beginner and experienced gardeners. Additionally, its compatibility with different plant types, including houseplants, vegetable gardens, and lawns, adds to its versatility.

However, some users may find the mixing ratio requirements a bit specific, and the need to apply it with every watering could be seen as a slight inconvenience. Despite these minor drawbacks, the product's benefits in promoting healthy green plants make it a valuable addition to any garden care routine.

Neptune's Harvest Fish & Seaweed Fertilizer 2-3-1 in a 36-ounce bottle is designed to enhance your vegetable garden, flowers, and foliage with stronger, more colorful growth and longer-lasting blooms. Its liquid form makes it easy to mix and apply whether by hand, sprayer, or drip line.

The fertilizer contains a balanced nutrient content (2-3-1 ratio) suitable for organic gardening, ensuring your plants receive essential nutrients without harmful chemicals. The relatively large 36-ounce size may require careful storage to avoid spillage or degradation over time.

Additionally, while compatibility with other fertilizers is generally good, it is always advisable to check specific plant needs and existing soil conditions to avoid nutrient imbalances. This fertilizer is ideal for gardeners looking for a robust, easy-to-use organic option to boost their garden's health and appearance.