10 Best Kelp For Garden 2025 in the United States

FoxFarm Bushdoctor Kelp Me Kelp You is a liquid seaweed extract fertilizer made from natural Norwegian kelp (Ascophyllum nodosum). Its liquid form makes it easy to use either as a foliar spray or soil drench, which is convenient for different gardening setups including soil and hydroponics. With an NPK ratio of 0.5-0-0.5, it provides minimal primary nutrients but focuses on boosting root growth and improving soil health through natural growth substances. This makes it best suited as a supplement rather than a standalone fertilizer.

The product is organic, environmentally safe, and non-toxic, making it a good choice for gardeners concerned about safety around children and pets. Instructions are straightforward: dilute with water and apply a few times during the growing season for optimal results. Because it lacks significant nitrogen, phosphorus, or potassium, it should be used alongside a more balanced fertilizer to meet your plants' full nutritional needs.

Some users may find the gallon size large if they have only a small garden. For those seeking a natural method to encourage stronger roots and healthier soil without harsh chemicals, this liquid kelp fertilizer offers a reliable option.

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.