One of our jobs here is caring for the greenhouse. We have been gathering and distributing seaweed on the beds since fall. The seaweed washes up in large amounts every few weeks or so. With buckets or tarps we haul it to the beds. We have been either leaving it out to let the rain rinse the salt off or washing it off ourselves. The salt is not good for the soil.
Then we spread it all over the beds inside the greenhouse and out and dig it in. There are many kinds of seaweed. The most important are the laminaria, also called driftweed or kelp. These are high in potash-especially the stems. Another is fucus or bladder wrack. It's potash content is low but grows well in sheltered waters where it is harder to find lamenaria. A third seaweed is ulva or sea lettuce. This weed is very rich in nitrates.
Seaweed in general contains approximately 7 pounds of nitrogen compounds, 2 pounds of phosphoric acid, 22 pounds of potassium, 36 pounds of sodium chloride and about 400 pounds of organic matter--per ton.
This photo was taken in the early fall and is a good example of how much seaweed washes up on shore.
