Seaweed is a natural fertiliser. Although there are over 12,000 varieties of seaweed they all grow in a similar environment and all contain nitrogen, phosphorous and potassium which is essential to plant growth.
Once seaweed mulches down it also encourages soil crumb to bind together which encourages capture and retention of nutrients for continued plant growth.
Adding seaweed mulch to plant beds limits the sunlight available to weeds much like any mulch however the sharp edges of dried seaweed, combined with the trace salt element is a highly effective deterrent to slugs.
Unlike other mulches or fertilisers seaweed does not contain weeds or insect larvae and therefore the possibility of adulterating soil with foreign bodies is virtually non existent.
Many types of seaweed also contain the following elements: calcium, chloride, iron, magnesium, sodium and sulphur. Trace elements include: boron, chromium, cobalt, copper, flourine, germanium, iodine, manganese, molybdenum, nickel, selenium, silicon, sulphur, tin, tungsten, vanadium and zinc.
As a result of the unique chemical composition of seaweed it is unsurprising that it is one of the most effective fertilisers available. Our seaweed is also, of course, completely natural – unwashed, untreated and unheated by anything other than the sun, to ensure the maximum retention of its constituent elements.