Is the salt and sand on seaweed an issue?

The storms we had a few weeks ago left lots of seaweed on the beaches. One of the councils paid $15000 to pick it up and dump it. None of the compost companies wanted it - sand and debris they said.

Seems to me that I could have got a truckload or two dropped off at my place. Not much nitrogen or phosphorous, but lots of trace minerals and iodine apparently.

I read somewhere that seaweed was too valuable to compost. Must have something in it.

Would the sand and salt be an issue if I used it to fertilise my
:?: 1) intensive garden
:?: 2) other growing sites

Mike

 

My Dad always said you have to wash seaweed well before using it, his family used it for many genarations in Ireland on their farm

Chop it up with a machete or a lawn mower and dig it in like green manure, or add it to your compost or use it as a mulch if you had that much of it.

I would love a truck load or three of seaweed too.

 

Here's a question for you bazman.

Where do you wash it?

Mike

 

I would use my gravel driveway for that type of thing. any salt would hopefully kill some of those weeds I can't be bothered pulling out.

 

G'day Mike

Seaweed by the truck-load, oh how lucky you are! I guess in a perfect world it would be advisable to wash it where it originally come from - the sea. But I imagine that it has been trucked to a central holding facility and that it is now sitting in great piles, heavily salt and sand laden?

Baz's idea for killing the driveway weeds with the runoff is a good one (as long as there is not bucket-full's of salt entering storm waterways, etc).

Peter Cundle (the guru from Tasmania) suggests that you leave the seaweed whole and use it as a surface mulch. He also claims that the little bit of salt residue remaining after having rinsed it is minimal in its effects on the target crop/plant/soil.

Have'nt tried it (the fresh stuff) myself. I have to resort to the stuff in the bottle as the nearest beach is too far away, and I believe there is a (environmental?) restriction on collecting it, too. However, next time I'm down the coast visiting my surfie-permie friends, I may bring back a bucket-full and try it.

Then again, perhaps there is some invironmental issues with bringing seaweed (and macro/micro-invertibrate sea-creatures?) inland? I guess I'll have to do the research first.

Cheerio,

Mark.

 

I'm with Peter Cundall

People who have been shipwrecked have survived for weeks on seaweed floating past them in the water - the level of salt within the plant is minimal (it does, after all, use photosynthesis hence uses fresh water in its tissues, not salt water), it would surely only have the surface salt on its leaves that has evaporated off as the plant has dried, as for the sand, if you live in a clay rich area, any extra sand on your mulching material would be a godsend!

IMHO

Cheers

SG

 

How wasteful our society is! and i'm sure there is a company in NZ collecting seaweed and processing it to make the liquid stuff you buy in shops. I shake my head in disbelief that no one did anything with it.

I use seaweed a lot. In the past i did wash it, but don't bother now. Partly because i have read that the amount of salt is miniscule, partly because there was no visible difference when i didn't wash it. and yep, the sand is probably a good thing for most soils.

In the past i used the kelp and larger seaweeds, apparently they have more goodness in them. Recently i have started using the finer sea grass (Zostera species). Mainly because it looks like it will do the job of pea straw mulch, but for free! If you are in Victoria the best places for these are along the coast near Portarlington, or Flinders. Huge banks of it washed up.

word of caution though, and this is in the Gardening Australia Veg growing book - it is actually illegal to collect and remove anything from beaches. I know it sounds crazy, but some councils may be quite strict about it. I haven't let it stop me, but i am more cautious and those 2 places i mentioned really do have enormous piles of it and it would be laughable being challenged about not being allowed to remove a tiny proportion of it.

anyone know whether mulching with seaweed would help prevent snail/slug attack? i wonder if the salt and sand would deter the little buggers???

billybuttongirl

 

just to clarify the removal of seaweed from beaches - i would imagine the restrictions are not really due to bringing sea fauna inland, rather the build up and decay of seaweed on beaches is a totally natural process and would probably support a whole host of invertebrates specialised at breakdown and nutrient return back to the sea. I guess if we all start taking the seaweed away we may disrupt this process.

Also, threatened birds like the hooded plover and the fairy tern nest on beaches. the seaweed drifts help camouflage them against predators and they feed on the invertebrates. There are probably other animals feeding on the invertebrates too.

As i said, i still take seaweed home, but only from where there is such an enormous amount that it is unlikely i would make much difference.

 

That's a fantastic approach to have, BBG

Its just how the aborigines, San Bushmen and other (frankly sensible) races view natural resources - take what you need, and leave a little for the other forms of life, and leave some for your grandchildren. The San always leave 1 tuber in the ground if they find 2 together, because they believe their children and grandchildren would be greatly disappointed in them if they dug in the same spot in 20 years time and found no tubers.

The remainder of the consumer-focused human population could sure learn some lessons from them, me included!

sprite

 

If only I had such problems as a huge mound of seaweed for the taking... 8)

I suspect the compost company didn't want sand and salt gritting up their windrowers, more than it would have affected the quality of the end product. Here in the US, most of the composting outfits are pretty formulaic...4 parts chips, 1 part straw, 1 part food waste, turn and water, voila. Something off the recipe book like seaweed may be new for them to handle. A shame...

In humid climes, the salt won't be a problem...it's a pretty small amount, and will flush away fairly quickly. But, I know you Ozzies have some problems with soils becoming saline in some areas, so watch out for that.

Cheers

Rich

 

I've collected seaweed with big gardening pots that have the holes in the bottom. I have specifically gone to beaches with fresh water taps so that I can rinse off the salt water... I agree though that in small amounts the salt wouldn't be an issue.
There are several seaweeds that wash up on the beaches here that are very edible and quite tasty. I don't know the different Hawaiian names but they are popular with the locals. You see people beachcombing for them quite a bit.

 

ABC's Gardening Australia ( https://www.abc.net.au/gardening ) will be covering the subject of seaweed fertilizers next Saturday, Feb 25 at 18:30.

The shorts I saw included images of fresh seaweed. I can only guess that Peter will talk about collecting and processing fresh seaweed.

derek

 

Seaweed

I've been using seaweed as my primary mulch/nutrient source for a while, and I agree with those who have suggested that salt/sand, etc. is not an issue: I never bother to wash it. In fact, I've little doubt the abundance of broken pieces of shell has added a reasonable amount of calcium to the soil.

One word of caution: watch where you harvest. Fresh seaweed, from just above or at the tideline is usually alright, but often there are tempting drifts of older, well rotted stuff higher up the beach. This frequently contains large amounts of seeds from fairly pernicious beach plants: and when they're introduced to the coddled realm of the garden, they do their thing in extremis.

 

Rich,
Funny you should mention salinity becoming a problem in Australia - as an ecologist, thats exactly what i work on! Our problems mainly stem from removal of natural deep-rooted vegetation which keeps the naturally saline groundwater levels low. The problem is exacerbated with over irrigation in a naturally dry environment. In Victoria anyway.

I think we'd have to add truckloads of seaweed for salinity to become an issue!

Woodschmoe - great suggestion about weed seeds, something i hadn't really thought of. And yes, sometimes i tend to go for the drier stuff further up the beach! (Haven't seen any nasties germinate yet).

cheers,
Billybuttongirl

 

Hello again BBG

Did you see the Australian Story on Peter Andrews a month or so ago? As an ecologist it would have greatly interested you, as he used weeds as bioindicators and freshwater lenses on top of salt within the ground profile to reduce salinity effects in the Bylong valley, which is a highly saline part of NSW?

sprite

 

Hi Spritegal,
No, i didn't see it! Damn! Problem is that i am always rushing around the garden until dark. Maybe they will repeat ot and i will keep an eye out for it - thanks for that.

cheers,
billybutton

 

Hello all. I'm new here and to Permaculture. I've got tons of seaweed on my property at all times of the year. Looks like I've picked the right hobby to study up on. Again it's frowned on to take it, but who's looking. I agree, take what you need

 

I'd have to ask the question here -- about exactly what you "need". The way I see it, we would all like to enrich our soil using seaweed but do we need to ?I wonder how sustainable it is to take away an important part of the oceans ecosystem, in order to have better gardens. I've been thinking this through lately as I see everyone pour seasol onto their vege patches. I'm wondering what the environmental cost is of mass producing this product.

 

I'm refering to MY needs not mass production. The piddly bit of seaweed I'd take to mix with fish bones and guts, helps feed my tomato plants. I'd never heard of that product until you mention it. As I said I'm new to Permaculture, but you sure fired me up to find out what "Seasol" was.
Having said all that, I think you're right about abusing a natural recource. Maybe if a quota was placed on it like there is on commercial fishing would help (if there isn't one). A hell of a lot seaweed gets washed up above high water mark with storms and naturally rots away, so the oceans would naturally replace what was lost in that way. A BIT more wouldn't hurt for personal use surely. It's a big ocean and I believe we are part of it as much as it is a part of us.

 

Seeweed is Great for the gardens,I never had problems with itb at all..I to got told that council dont like people taking it away..(dont know why),but i used to take chaff bags and fill them in my car boot,If anyone say anything,Id be curious,as no one else takes it,...Apparently the softer kelps are beter they break down easier,see grassses are good but break down slower,never had any probs with salt damage to my plants,in fact i was encouraged to use it by more experienced permies,as.....apparently because we all originally came from the seas,we are all bound by the seas,we are the seas,the seas are us,etc etc.Hard to explain,The stuff is so good you never need enough o it to hurt your land,Its just a super allround aitive to our crappy aussie soils,when i used it i was on sand,and lived 1 hour away now im 3 hours away,Me thinks that Seawed is like a lot of other things/remedys,
Its So good a product to use,the powers that be, try to make sure that no one uses it to get any real use/benifit to it.... Another example is river weeds
instead of governments whinging about all the excess weeds in waterways,started using it for more sustainable purposes,maybe wed have cleaner rivers with less fish life destruction in the proccess.a lot of water weeds can be used as compost accelarators,food for chooks and ducks,
and Ive heard maybe as an alternative bio fuel..

Tezza