What Seaweed is Best for a Seaweed Fertilizer
Different methods are used to create seaweed fertilizer. While some use emulsions, which are made by heating up and then fermenting the seaweed with water, others are simply liquefied, decayed and applied directly via a fertilizing spray.
If you are intending to make your own flower fertilizer using seaweed, use fresh seaweed whenever possible. Avoid dry or seasoned seaweed as the preservatives and seasonings can harm the beneficial microbes that grow in the soil and on your plants which protect it from disease and parasites. For agricultural fertilizer, it is recommended that you purchase larger containers of seaweed fertilizer because it can become very expensive to make and it can contain more trace elements and additives that can supplement and feed your plants.
If you are gardening vegetables on a smaller scale, homemade seaweed fertilizer or emulsion is capable of performing as well as commercial fertilizer. The difference is the additives and you can always add other ingredients (Epsom salt, apple cider vinegar, molasses) to the mixture in order to achieve a certain pH or to add a particular nutrient your plant needs.
The best seaweed to use is fresh, organic seaweed that is clean and ready for the controlled decaying process. This ensures your plants are given the nutrition they deserve.