sea weed

If it is from above the high water mark and old seaweed then you do not need to do anything other than use it, either as a mulch or dug in. If it is fresh then it is better if you compost it first.
Wish I had a load of it, wonderful stuff!

I would wash it first, the salt can damage the soil

Thanks.
Ali

Stuff from above the highwater mark has already been washed by the rain and the amount of salt remaining is not enough to do any damage to your soil. We dug barrow loads (actually car loads) into my father's garden which had virtually no soil worth talking about. Everything he planted grew like mad afterwards.
Composting fresh seaweed would be enough to remove any salt from it.
As I said I wish we lived near the seashore, I would be down there after every high tide collecting it!
Jersey potatoes used to be grown in fields covered in seaweed collected from the shore until the EEC banned the practice.

I read in the Gardening Telegraph at the weekend, that collecting seaweed from the beach was illegal, which surprised me. That only if the beach was privately owned could this be done. I can't imagine why this would be so unless there are permit holders who have the right only?

Well, yeah I can see it would upset the natural balance if lots of weed was taken. I'll visit a friend who wants their lawn cleared.
The nuclear residue bothers me a wee bit. the currents will bring the stuff from Sellafield up the West Coast.