Seaweed`

No.125

Does anyone here use seaweed annually to improve their soil? im tyring it for the first time this season..im just wondering how you should apply it to the soil at this time of year? i've layered it over the surface rather than dig it in..just incase it needs to be removed!

is it ok to add seaweed to soil where root crops will grow? or will it cause forking in carrots,parsnips and such.

thanks

Hal Emmerich

Would Salt be an issue using Seaweed?

No.125

no..salt content is not an issue...i did look into that. apparently seaweed is excellent fertilizer.

redser7

I've been reading up a good bit lately about seaweed. It actually isn't a great fertiliser at all. The NPK values are very low compared to something like manure or compost. But it is still great for the soil and plants. It's value lies primarily as a soil conditioner. It creates airy crumbly soil texture and is also great at retaining moisture. It contains rich nutrients and trace elements that you wouldn't find in manure and compost. It also contains growth hormones which stimulate plants to better growth. It gives plants increased resistance to disease and overall makes them healthier. It can be dug into the soil, added to the compost heap or used as mulch.
But it seems that all its great benefits are more to do with their effect on the soil rather than a fertiliser for the plants. So if you are using seaweed you should probably also use some sort of fertiliser like compost, manure, fish blood and bone, chicken pellets, growmore etc.
There are 2 schools of thought on whether to wash the salt out or not but it looks like it is not necessary. The amounts present are negligible and would easily be washed into and through the soil by rain without damaging plants or the overall soil. Makes sense when you think about how widely used seaweed was and is by coastal farmers. There's no way they would have been able to wash the huge amounts they used.

No.125

cheers redser...great info there.

redser7

I hope I didn't give the impression that it is not a fertiliser at all, it is just low in NPK values. But given the other benefits it has it probably improves plant growth in a way that makes up for the low NPK values. When it works its magic it efficiently releases locked up nutirents in the soil in a way that makes them readily available to be taken up by the plants. Research gets complicated beyond that explanation :-)
Oh and the salt in it goes some way to detering slugs!! What more could you ask for

Clare man

I have been using seaweed for the last number of years and I have never washed it, though I am not cutting it, but use washed up seaweed.

I use it as mulch for raised beds and find it is very effective, tpyically I alternate every second year with manure. As Redser said it is a great soil conditioner, ie look after the soil and you will get great crops. there will be no issue in growing carrots etc next year.

I also use in Polytunnel where I dig it,as opposed to use a mulch, soil is in great condition. I use it outside for apple trees, fruit bushes, hedging where it is a great mulch. I have been advised not to use Manure on apple trees

One thing to watch out for is the insects, collect by trailer if you can, bagging and putting into car boot, will leave a loty of hoppers in your car for weeks.this is the best time to collect, especially after iwinter storms

Hal Emmerich

Nettles are supposed to contain lots of trace elements to, I compost a good bit of them every year and dig in, no shortage of them around.

Degsy

Hal Emmerich wrote: »

Nettles are supposed to contain lots of trace elements to, I compost a good bit of them every year and dig in, no shortage of them around.

High in nitrogen...you can also soak them for a number of weeks in water and use the liquid as a fertiliser..either diluted or neat.

CJhaughey

The Monks that lived on the Skelligs used to draw seaweed up to rot down and make soil so they could grow veg and herbs.
All available evidence seems to show that seaweed is remarkable for growing stuff in.

kkth0360

Hi, complete beginner here! I am planning to install a 14” high raised bed over a patch that was previously part of a lawn. I have removed the grass / turf and dug over the patch to remove large stones and some tree roots, which I know is probably not strictly necessary since the raised bed is reasonably deep but I figured it probably wouldn’t do any harm. I’ll be filling the bed with a soil / compost mix. My question is this: I have collected a couple of bags of fresh seaweed from a local beach and I wondered if there is any benefit to laying this down over my patch before I put the raised bed on top? I’m thinking it might help kill off any weeds et that might be in the soil and also provide nutrients for any of the deeper rooted veg like carrots and parsnips? Or would I be better off to let it rot in the bags and use it later to add to the surface of the raised bed? I’d appreciate any advice. Thanks