Seaweed Mulch

[cannamaniac]

Has anybody tried this? I can get as much seaweed as I want and usually spread it around the garden but so far not on the bamboos. I read in Michael Bell's book "Temperate Bamboos" that they don't like the salt content and that it is used in the orient to limit the spread of certain bamboos.
However I noticed this on the scottishbamboo.com site
"Q: When should I feed my bamboo?
A: We recommend feeding your bamboo plants in early Spring, i.e. at the beginning of the growing season. Another good time to give an extra feed is in Autumn, with a low nitrogen feed. Our organic seaweed plant food is ideal for feeding throughout the growing season.
So does this mean liquid seaweed feed is alright but the raw weed isn't?
By the way I always give the seaweed a rinse before using it around the raspberries,cannas and spuds.
I might have to set up an experiment

[needmore]

There is anecdotal reference to using seaweed buried at the perimeter of a grove to stop it's spread. I don't recall where I read that but I filed it away as don't feed with seaweed, Perhaps it is not the case but since there are alternatives...

[johnw]

Brad - I recall that too. Could have been Meredith or the Bell book.

Salt said not to be good so best check the conternt especially if you're not in a high rainfall area.

john

[steffen]

A few thoughts on this:
Bamboo is of course not very salt tolerant, but it is also not exceptionally salt sensitive.
This paper
http://link.springer.com/article/10.1079/IVP2002389
e.g. indicates that the threshold for Dendrocalamus is around 50 mM NaCl (approx. 3g sodium Chloride /l or kg). This is in the range as for many other non salt tolerant higher plants.
Dried seaweed contains 20-70 g NaCl per kg (probably translates to 2-7 g per kg fresh seaweed, or even a bit less). This is of course a lot, but if you "apply" so much seaweed to you bamboo that it will control growth, it's very likely that you will also poison other not exceptionally salt tolerant plants near by.
Regards, Steffen

[cannamaniac]

Thanks for your thoughts on this.
I think a little experimentation is in order

[cole]

Seaweed might be okay as an amendment if your soil has a low pH to begin with, but if you're in the neutral range and then increase salinity, you risk inhibiting microbial activity. If your soil is alive, your plants will thrive, so I'd be super careful with seaweed. I sure wouldn't pour sea water - which is 10x more alkaline than pure water - in my garden.

It's just one way of doing things, but I shoot for the most sustainable long term soil conditions possible. Instead of tilling the crap out of soil - which is kind of like dropping a bomb on an underground city - I prefer to amend with composted leaves activated by nitrogen from coffee grounds (brewing removes acidity). Most of my gardens are 20% biochar, but far and away the greatest compost is plain old leaves. Kitchen scraps are saved for a worm bin, since they are more of an invitation to pests. My early spring rhizome feeding is from cleaning out my goldfish pond, which sits under a canopy of oak and ash trees.

The Amazon Rain Forest has (terra negra aside) some of the worst soil on the planet. It's red clay. All that nutrition comes from its own fallen leaves. I shake my head when neighbors bag up and send off their leaves, then drop $200 at Home Depot for compost and other ferts.

My apologies for being long winded. Peace.

[cannamaniac]

Seaweed might be okay as an amendment if your soil has a low pH to begin with, but if you're in the neutral range and then increase salinity, you risk inhibiting microbial activity. If your soil is alive, your plants will thrive, so I'd be super careful with seaweed. I sure wouldn't pour sea water - which is 10x more alkaline than pure water - in my garden.

It's just one way of doing things, but I shoot for the most sustainable long term soil conditions possible. Instead of tilling the crap out of soil - which is kind of like dropping a bomb on an underground city - I prefer to amend with composted leaves activated by nitrogen from coffee grounds (brewing removes acidity). Most of my gardens are 20% biochar, but far and away the greatest compost is plain old leaves. Kitchen scraps are saved for a worm bin, since they are more of an invitation to pests. My early spring rhizome feeding is from cleaning out my goldfish pond, which sits under a canopy of oak and ash trees.

The Amazon Rain Forest has (terra negra aside) some of the worst soil on the planet. It's red clay. All that nutrition comes from its own fallen leaves. I shake my head when neighbors bag up and send off their leaves, then drop $200 at Home Depot for compost and other ferts.

My apologies for being long winded. Peace.

I usually use home made compost,leaf mould (1 or 2 years old) and lawn trimmings.So you're preaching to the converted .
My soil is alkaline.Have you heard of the white cliffs of Dover? Well they are just down the road.We are sitting on chalk here.But the top soil is fairly deep here and I am doing what I can with the bulky organics.Most thing seem to grow here except acid lovers.And the bamboo seems happy too.

[marcat]

why does every one assume seaweed is heavy in salt? For a plant to grow in a marine environment it has to have the ability to filter salt out of the water it up takes.
I have used sargassum for mulch on bamboo no problem so far.
MarCat

[Tarzanus]

why does every one assume seaweed is heavy in salt? For a plant to grow in a marine environment it has to have the ability to filter salt out of the water it up takes.
I have used sargassum for mulch on bamboo no problem so far.
MarCat

True. I always use salt when I eat salt-water fish, they have the same yucky flavour without it as the ones from fresh water.

[T9D]

why does every one assume seaweed is heavy in salt? For a plant to grow in a marine environment it has to have the ability to filter salt out of the water it up takes.
I have used sargassum for mulch on bamboo no problem so far.
MarCat

If you harvest it it's basically a huge mop of sea salt water, and then that all dries and tons of salt is left on it. You could obviously wash it all down but that is a ton of work and wasted water. I'd imagine it would still be hard to get it totally salt free. But maybe enough. If you're up for it I don't see why you couldn't use it I guess. I'd always worry though I didn't get enough of it off and one day it was to much or it built up over time and would do some damage.

[cole]

why does every one assume seaweed is heavy in salt? For a plant to grow in a marine environment it has to have the ability to filter salt out of the water it up takes.
I have used sargassum for mulch on bamboo no problem so far.
MarCat

Depends on how it's processed. The seaweed left on our shore house dock has incredibly concentrated levels. But there are a million types of seaweed, and lots of ways to harvest. I'm a big believer in using what's locally available, so I'd definitely soak and then compost anything directly out of the ocean if that's where my garden was.

[Tarzanus]

I'd guess they at least keep it for a while, exposed to the rain. Washing can also be an option.