Collecting seaweed for composting

I live on the north coast of California and I'm interested in collecting some seaweed from some rocky beaches to compost to add to the garden. Does anyone have any experience with this? Is there any particular species of seaweed I should seek out or avoid? A mix of all of them? I'm planning to mulch it up with my lawn mower and mix it in with a combination of manure and wood chips and let it compost for 5 or 6 months. Should I rinse it to get the salt off or is that just a bit more mineral content? Any thoughts would be much appreciated. Thanks

In some places there may be legalities.

I have used a wide array of seaweed.

Some places clean up large amounts of seaweed from swimming beaches. You might want to see if this is being done anywhere near you. They might have a big pile somewhere, that you could benefit from.

Port Authorities and marinas sometimes clean up seaweed.

Dale Hodgins wrote:In some places there may be legalities.

I have used a wide array of seaweed.

Some places clean up large amounts of seaweed from swimming beaches. You might want to see if this is being done anywhere near you. They might have a big pile somewhere, that you could benefit from.

Port Authorities and marinas sometimes clean up seaweed.

I'm not worried about the legalities, there are very remote beaches here with tons of seaweed of a half dozen or so species. Obviously I will practice my best foraging ethics when harvesting. I am mostly curious about the differences between the species. I know that there is kelp, nori, wakame, and 3 or 4 other much smaller species. In the end I may just harvest a tote full of a mix of them and see how it goes.

I don't have firsthand experience with seaweed, but I read a lot, and everything I have read says that seaweed is very beneficial to your soil. If I lived near the ocean, I would harvest as much as I possibly could. Also according to what I have read, you do not need to rinse it off. unless you were applying absolutely huge amounts, the sodium will not build up enough to be an issue. And your soil will benefit from the dozens of other minerals both in and on the seaweed you harvest. Scott Nearing, of "The Good Life" fame, used to regularly drive his pick-up truck down to the beach and harvest as much as he could fit in the truck. If I remember correctly, he applied it directly to the garden as a mulch. I could be remembering wrong though, he may have composted it first.

I was on Monhegan island, Maine, a few weeks ago, and I saw several gardens there with seaweed mulch. Sorry I don't have any info on specific species, but from what I have read, I think it is all good for the soil. And I don't think you need to compost it first unless you really want to.

Get yourself a copy of a book called Fertility From the Ocean Deep.

Oh I just remembered I read somewhere about old time farmers in Scotland, they used to harvest very large amounts of seaweed, and spread it on their fields.

carl gibson wrote:

Oh I just remembered I read somewhere about old time farmers in Scotland, they used to harvest very large amounts of seaweed, and spread it on their fields.

I was on the Isle of Skye in the spring and you can see all over the island the patterns left in the ground from the old practice of runrig cultivation, of which seaweed gathering was an important part.  There is some interesting first hand information here: http://www.hebrideanconnections.com/subjects/38010 about using seaweed.

most of the people i know involved with organic /gardening growing are addicted to using seaweed , it boosts or replenishes soils with trace elements as it decomposes and has a natural  binder in it which bonds soils , its been a long traditionally used ingredient in soil building here in ireland in particular on the small offshore islands for potato growing and fields/ grass dressing and still is .It tends to be applied directly onto the soil and left to breakdown into it  rather than composting it .

I use a lot of it on my farm, but I do not collect it. We have a plant here that makes gelatin from it and their byproduct is what I get. They used to dump it in a landfill until my cousin who works there suggested they give it to farmers. It used to be free but now they charge $1.90 a ton for the cost of trucking it. It sucks, but it still is in high demand and only in the dead of winter can you get it, or be put on a 6 month waiting list.

The stuff I get is a type of kelp, but it is imported from another ocean and NOT the Atlantic. And surprisingly the main reason to use it on the fields is not because of its fertilizing and composting properties, but it being a cheap lime substitute to get the PH levels up. Generally to the East of the Mississippi River the soil is low in PH and on the other side it is high in PH, so I might be wary of just applying it willy-nilly because here we swear by it, but also have 5.2 PH soil!

The great thing about it...while it primarily is used for lime purposes, is that it does have trace minerals that are hard to get elsewhere...kind of a freebee.

The downside is that it is kind of weak as far as lime and fertilizer...it literally takes TONS of it. In fact it takes 10 tons to equate to 1 ton of lime. This has serious limitations. Because of the volume, it would smoother grass ground if spread at the proper ratio to bring the soil up in PH levels and fertilizer levels in one shot. So using the stuff is a long term strategy on grass ground: a little every year. Obviously on tilled ground that is not an issue, and is what i do when crop rotating; pound the algeafiber (seaweed) to the ground and till it in. It also means spending some serious money on fuel since you have to move 90% more of it which can add up in diesel fuel costs. It also smells kind of bad when you first break into it; like rotted fish. No worse then manure for sure, but in Maine I am protected by the Right to Farm Act so smell is a non-issue. For states without the right to farm act, it might be a problem.

As long as the availability is good, I will continue to use it. Mostly it means taking loads of it in January when other farmers do not want it. That means bulldozing roads through the snow so trucks can pile it up, which is an additional cost, but such is life farming. Ultimately, I like the trace minerals, and cost for cost, it is about the same as mill lime. Mill lime is $22.50 per ton, BUT it takes .85 tons of mill lime to equate to 10 tons of algeafiber (seaweed) and mill lime has no trace minerals. Some fertilizing qualities (p) but not a whole lot. It really is a toss up money wise...

While no one mentioned this; I also use fish guts taken from a local fish processing plant. That is really good fertilizer and has no smell because they inject the fish guts directly into the soil and is immediately covered up. I alike it to the Indian side of my ancestry where they planted a seed of corn with a "fish". I put fish in quotes because it was likely lobster, something they could just pick up from low water at low tide. I think it is injected partly because of the smell, but also to keep animals from being attracted, and also from the loss of nitrogen. I like it though as a sea derived fertilizer.

Whenever I hear about that seed of corn to a fish thing, I assume that they were fishing for certain types of good eating fish and in the process got a bunch of bony trash fish as a by catch. It's hard to imagine anyone putting perfectly good fish in the ground. It's probably just as likely that these holes were filled with heads, backs and guts after fish were filleted.

On bad smells. Just about every bad smell in nature is protein-based. This means that if you can smell something bad, your nitrogen is becoming airborne and leaving the farm.

I also live in NW California and use seaweed as much as I can, collecting when it is abundant. Unfortunately, I have seen almost none wash up this year in my usual spot.

Dale Hodgins wrote:Whenever I hear about that seed of corn to a fish thing, I assume that they were fishing for certain types of good eating fish and in the process got a bunch of bony trash fish as a by catch. It's hard to imagine anyone putting perfectly good fish in the ground. It's probably just as likely that these holes were filled with heads, backs and guts after fish were filleted.

On bad smells. Just about every bad smell in nature is protein-based. This means that if you can smell something bad, your nitrogen is becoming airborne and leaving the farm.

Good observations Dale,  it is indeed the skeletal remains, head and guts of fish from filleting that we use. You dig a hole, lay in the fish remains in the bottom of the hole and cover with soil then plant the seed. Holes are spaced about a forearm apart. Once the corn comes up we plant beans around the new corn stalk and then we come back and plant squashes in the open spaces.

Redhawk

I have never found a sea weed that would not make great compost or wouldn't do good things when dried and ground up.

On the west cost, Iodine kelp is the major species and is easy to identify from the big leaves and air sacks. smaller species that grow nearer the land mass are also great for our gardens.

Redhawk