If your soil could use a micronutrient boost, kelp can help! Some chemical analyses have shown up to 60-70 vitamins and minerals in kelp meal fertilizer. The relatively low levels of nitrogen and potassium provide key macronutrients for growth and hardiness without burning young plants. Iron and manganese help with the photosynthesis process. Kelp also contains important enzymes and plant growth regulators that encourage plant growth by assisting with cell division and elongation.
Kelp meal comes from a highly renewable resource. Kelp seaweed is a kind of marine algae that grows very rapidly – up to 3 feet per day! So harvesting the seaweed for fertilizer does not overly deplete the supply. One of the reasons kelp is so rich in micronutrients is that it filters seawater, collecting a diverse range of marine nutrient sources, such as fish waste and chitin from shellfish.
The nutrients in kelp meal are also released rapidly, over a month or two, making it a great choice for container plants or plants with a shorter life cycle. Because the plant is low in cellulose, it doesn’t take soil microbes as long to break down the nutrients and recycle them for plant uptake. And of course, after the nutrients are released, kelp meal contributes humus to your soil to keep your soil structure in stellar shape.