Not everybody has the luxury of living near the sea, but if you do, as I do, then after an autumn storm is the time to go and load up on seaweed.
The benefits are many.
1/ It is free
2/ It is natural and proven over thousands of years as a good all round fertiliser
3/ Slugs don’t like it because it is slightly salty
4/ It comes out of the sea so there is no danger of it carrying plant pathogens or stray weed seeds like home made compost
5/ It acts as a weed suppressing mulch as well as a slow release fertiliser
Apart from the fact that you might look a bit silly to some people, lugging seaweed up from the beach, it is perfectly ok. Although, with the growing popularity of vegetable gardening I think it is now regarded as less eccentric than it used to be, and this morning a lady approached me for advice on whether she should put seaweed on her asparagus; of course she should! It is also a perfectly legal activity, nobody owns the beach, or the seaweed.
I have know idea as to what the best seaweed is for the job. I assume that like terrestrial plants, each type has a slightly different chemical make-up and therefore adds something slightly different to the soil, so I gather a bit of everything. The smaller bits I spread around the greenhouse bed, bigger things like kelp, with thick stems and those funny roots, I put into the compost heap or dig into the vegetable patch, I sometime find these months later slowly breaking down in the soil, releasing nutrients as they go.
Bladderwrack tends not to rot very quickly, and sits on the surface for a long time, alternately drying and rehydrating with the weather so this becomes a slow release fertiliser, but in the mean time acts as a mulch.
As well as using seaweed immediately you can keep a bin of it, a bit like comfrey, and tap off the liquid as it decomposes then dilute it and use it as a general fertiliser, but beware, it stinks, horribly. This is best done in the spring and early summer time when you need it most, rather than now, in the autumn.
If you grow asparagus, then seaweed is a fantastic thing, you should pile it high on your asparagus mounds at this time of year. Asparagus is salt tolerant and you will be surprised as to how quickly it starts to soak in, leaving the tougher stuff as a mulch in the spring time to help keep the dreaded slugs and snails at bay.
With regard to salt. Seaweed is going to be slightly salty, but i don’t think I have ever had any ill effects because of this. This morning I gathered weed that has been rinsed slightly by overnight rain, but if you were worried then you could fill and empty the bin with fresh water just in case.