Mauimeadows
Newly Registered
Posts: 1
Joined: Thu Jun 28, 2012 2:39 am
Location: Maui Hawaii

composting seaweed from the ocean?

Can I throw seaweed on my compost? as green, and add dry? I'm very new composting. :roll:
Be the change you want to see.

tomc
Super Green Thumb
Posts: 2665
Joined: Sun Apr 10, 2011 6:52 am
Location: SE-OH USA Zone 6-A

If it was alive, it will rot.
Think like a tree
© 2016 Invisable Inc.

User avatar
ReptileAddiction
Greener Thumb
Posts: 866
Joined: Sun Jun 17, 2012 4:52 am
Location: Southern California

I don't see why not?

User avatar
webmaster
Site Admin
Posts: 9189
Joined: Sun Feb 08, 2004 5:59 pm
Location: Amherst, MA USDA Zone 5a

Salt content might be problematic.

toxcrusadr
Greener Thumb
Posts: 969
Joined: Thu Sep 09, 2010 8:50 pm
Location: MO

I don't live on the coast and have never composted seaweed, but lots of folks do it. I think the salt will not be a problem as long as it is not the dominant ingredient in your pile.
Tox

estorms
Senior Member
Posts: 263
Joined: Thu Dec 15, 2011 12:04 pm
Location: Greenfield Township, PA

I used to live close to the ocean. Most of the people there rinsed it off. I never used it because I do not like the dead fish smell.

bell7283
Full Member
Posts: 47
Joined: Thu Aug 04, 2011 2:04 am
Location: Rhode Island, USA

I have been thinking of adding seaweed to my compost for a while, so I have been asking around. I have heard good things so I think I'm going to give it a try. Washing if off first is a good idea though.
Zone: 6A

User avatar
gixxerific
Super Green Thumb
Posts: 5889
Joined: Fri Jun 26, 2009 9:42 pm
Location: Wentzville, MO (Just West oF St. Louis) Zone 5B

Use it in moderation meaning add a bunch of other organic material to it as well. Cause like webbie said the salt can build up and wreck your soil.

Everything in moderation.

toxcrusadr
Greener Thumb
Posts: 969
Joined: Thu Sep 09, 2010 8:50 pm
Location: MO

I'm not sure salt would build up much in a Hawaii soil, which is likely to be very sandy and highly leachable when it rains. If it was a clay soil I would be more concerned. Certainly nothing wrong with rinsing it off though, just to be safe. You'd just have to do it somewhere other than your own yard, though!
Tox

imafan26
Mod
Posts: 11395
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Ma'o farms on Oahu uses it. They do dry and leach the seaweed before putting it in the compost pile because the salt is a problem. It is only added in small amounts.
Happy gardening in Hawaii. Gardens are where people grow.

User avatar
Lucius_Junius
Cool Member
Posts: 71
Joined: Fri Feb 03, 2012 3:06 am
Location: Nova Scotia - Zone 6a

Seaweed (and fish) has been used for both compost and mulch by people who live near the ocean for millenia. About ten years ago my neighbor spent an entire day bringing up tractor loads of it to compost for his garden. In New Brunswick in the early 19th century, Acadians planted their potatoes between two herrings. In fact, their herring fishery existed almost entirely to supply the compost they required for their fields and gardens. I've always wanted to try the herring method.

If you google seaweed as mulch, there are some good articles on it. I'll advise you that it does shrink a lot.

Most people say the salt content of seaweed is actually minimal enough that it doesn't do any damage, and that rain water tends to have washed it out if you're getting your seaweed from up the beach. Collecting seaweed that's been washed and rained on a few times means less salt, less damage to the environment, and that some of the composting has already been done for you. It's also usually a little drier, so you won't have sea-water running all over the place as you take it home. Others add that if you're worried about it, you can simply lay it out in your driveway and rinse it off with the hose.

imafan26
Mod
Posts: 11395
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Re: composting seaweed from the ocean?

Rinse the seaweed first and dry it to get rid of any salt crystals. As longs as you do not put a lot of seeweed in the the compost it is probably o.k. You can put too much. The garden where I volunteered got a truckload of seaweed after an ocean clean up. It was dried but not washed. They put too much of it in the compost pile. A year later when the compost was tested it was too saline to use. It took another year and adding more material to it dilute and leach it out.
Happy gardening in Hawaii. Gardens are where people grow.

Return to “Composting Forum”