Yesterday my local community group sent out an alert that massive piles of Sargassum seaweed (Sargassum spp.) have washed ashore here on the East Coast of Florida. My littlest gardener and I headed over to a beach side park in Ormond so she could play a little and we could collect some seaweed for the garden.
Coastal areas all over the world use seaweed that washes up onshore as sources of agricultural soil enrichment. Many different species of seaweed can be used. Our most common here in Florida is Sargassum seaweed, which adds organic material to the soil and can be found year around. It has been estimated that there are 10,000 square kilometers of seagrass in the Gulf of Mexico, and 85% of that is in the waters of Florida.1
Once harvested the seaweed can be used in a variety of ways, such as in compost, soil amendment, in place of peat moss, and as an organic mulch. I have even read about some gardeners making composting tea out of it for liquid fertilization. Some chop up their seaweed to make better use of it as well.
Seaweed must be washed to remove salt for most uses. This was fun for my big gardener and I do when she came home from school. We removed trash debris and sea pencils from the seaweed piles that I had collected. We washed most of it and put it in the compost bin that we will use in the spring. Then we left some in the wheel barrow full of water to soak over night. We are going to wash it more thoroughly and apply it directly to the plants already growing in the garden.
We then had to wash ourselves, it is stinky like fish! :)
1 – UF IFAS Extension – Solutions for your Life 2007-2011