Kelp Can Help!
The benefits of sea kelp to humans, animals, and plants alike have proven themselves to be self-evident for many years. Kelp thrives in clean, unpolluted ocean waters and acts much like a filter as it absorbs the vast array of minerals needed for plant and animal growth and wellbeing. Kelp also contains amino acids, vitamins, and plant growth hormones (called plant growth regulators) including auxins, cytokines, and gibberellins. Typical uses include food, nutrient supplements, skin and hair products, animal feeds, fertilizers, and soil conditioners. Whatever application we assign to it, kelp has always seemed to improve the subject’s health.
The Nature of Kelp
The species most often used in everyday applications and research studies is a species called Ascophyllum nodosum, or Norwegian Sea Kelp, from the North Atlantic. It grows in the mid-intertidal zone where shifting tides alter the depth of the water drastically every day. When the tides are high, the kelp’s buoyancy allows it to reach near the surface where the sunlight is plentiful, and it can perform photosynthesis in its fronds and stems. Kelp is called a sea plant, but it is not a plant at all. It does not take in water and nutrients through roots. Instead, it absorbs all essential elements needed for development from the surrounding waters- foliar feeding to the max!
Kelp is extremely sensitive to the surrounding ecosystem and will only thrive in areas that are relatively unpolluted, making their presence a good indicator of clean water and in turn a healthy aquatic ecosystem. Sustainable harvest is important because kelp can grow up to 10 feet tall, and fields of it make for an excellent habitat for ocean life both small and large.
Upon maturity, kelp is harvested by cutting it about a foot up from the holdfasts which allow enough surface area for the kelp to create new growth. The kelp is then rinsed with water to remove excess sea salts, dried under the sun or in commercial dehydrators, and lastly put through a manufacturing process. Common techniques for manufacturing sea kelp for use as a fertilizer include chemical alkaline extraction, cold processing, and simply grinding the dry kelp into coarse granules. Kelp that has gone through the chemical alkaline extraction process is the most commercially available type and comprises the majority of kelp products on the market today.
The Benefits of Kelp
Enhanced Seed Germination
For years, growers have been soaking their seeds, usually for around 24 hours, in a solution of kelp and water. The result is often a seed that germinates and sprouts at a faster rate than normal. Why does this work?
Plant growth regulators called gibberellins are involved in the creation of enzymes that stimulate the breakdown of the seed coat (shell) and the stored proteins inside that help feed a sprouting seedling. Sprouting seeds will create gibberellins on their own but introducing them at such an early stage via the kelp can speed up the process. This is helpful for seeds that are difficult to germinate or those that take a long time, such as basil seeds.
Aid in the Rooting of Cuttings and Increasing the Root Mass of Seedlings and Transplants
The plant growth regulators contained in kelp called auxins have the ability to both initiate and increase root growth. Supplying young seedlings with a kelp and water solution can also help to encourage rapid growth and establishment of the root system. A larger more robust root system is advantageous for a young plant as it allows the plant to absorb water and nutrients more readily.
Similarly, treating transplants of all ages with a kelp and water solution at the time of transplant can reduce “transplant stress” and allow the plant to quickly acclimate to the new rooting environment, leading to less plant loss at this early growth stage. Using kelp throughout a plants whole life cycle will most often result in a healthy, sprawling root system that can support ample growth.
Increased Bud Production in Flowering Plants
Plant growth hormones work both together and alone, and the concentration of one in comparison to others can result in a host different plant responses. For example, when auxins are in greater concentrations compared to cytokinins, root growth is accelerated, and when cytokinins outnumber auxins, lateral shoot development is increased. In flowering plants, more shoots will correlate into more flower bud production. Treating a plant with kelp as it transitions into the flowering stage can result in a dramatic increase of flower bud sites. Applications during this stage can be made via the roots or through spraying the plant’s leaves known as foliar feeding.
Kelp’s Plant Growth Regulators
Kelp is marketed and sold as a specialty fertilizer but the most important components of the product are the plant growth regulators. If a grower wanted to use kelp as a main source of plant nutrition, then the overall quantity needed for each application would be so high that it would not be considered sustainable to either plant growth or a grower’s budget. You won’t even see micronutrients on a kelp product label because they are in such small amounts. So if plant growth regulators are such an active component in kelp products, why are they not included on the label?
The reason for this is how the regulation of plant growth regulators is approached. The department of agriculture for each state is in charge of regulating the sale and distribution of fertilizer products, but plant growth regulators are managed by the same regulatory arm of the EPA that handles pesticides and other products that enable a grower to manipulate plant responses. Fertilizers simply do not stimulate the types of developmental responses that one sees with the use of plant growth regulators of any type. Registering a product through a state agency as a specialty fertilizer is an easier process and less costly when compared to obtaining an EPA registration number. Since kelp contains essential plant nutrients, most companies that manufacture and distribute kelp products take the path of least resistance and register their product as a specialty fertilizer. When a product is registered as a specialty fertilizer, the only claims allowed on the label are those for elemental nutrients and/or soil/plant amending ingredients. Thus these labels will not include claims or references to the most important ingredients- the plant growth regulators.
More to Kelp Than What’s on the Label
The overall benefits of sea kelp should not be understated but it is of great importance to understand as much as we possibly can about the products we use in our gardens. Often the main stated purpose of a material is not the only purpose it can play with respect to plant growth and development. Sometimes the underlying benefits are the most desired. Realizing this will make it easier to understand how we can properly utilize the benefits of kelp for all of the plants we grow.