This time of year the seaweed is growing around my dock/boats like wild fire. I usually use a seaweed rake to remove it and let it float down river.

As summer creeps to an end here in Michigan, I'll be clearing out my vegetable garden and rototilling it before winter. I thought about harvesting the seaweed for the next few weeks and saving it in 50 gallon drums. I'm thinking about rototilling the seaweed into the garden soil in preparation for next years vegetables. Thoughts?

I'll also be doing quite a bit more fishing in the coming weeks before winter. We often catch fish species that are invasive to The Great Lakes and are instructed by the DNR to kill them. I was thinking about adding the fish to the seaweed combost barrels. Thoughts?

Also, this is fresh lake water... not salt ocean water.

Here's some information I ran across that leads me to believe this is a good idea.

Click here for more information

I'd compost the seaweed and fish (perhaps together with another good brown) and use that. Even seaweed, fresh and decaying, will suck nitrogen and oxygen from the soil.

The only downside I see in using fish is...well, the smell as it composts. You can control that with plenty of browns.

Time was, the pilgrims used to use alewives to fertilize the soil (back then, they weren't endangered, they were common and almost useless as a food fish).

I'll have plenty of leaves to use as browns. They're already starting to fall from some of my trees. I think winter is coming early this year.

Do it!

I've been tempted to do it with rinsed salt-water kelp. It's just that the timing is always wrong, and when I have access to the kelp (vacation), I am falling behind on basic maintenance of my yard - so no extra time to spare when I get back. I've done research on it though, and it's all positive. Salt-water kelp has more trace elements, but freshwater seaweed is quite useful anyway.

The guy that owns the place that I rent on vacation buries the carcasses of the cleaned fish and swears by the results in his garden.

I haven't done it yet (but it works with tow truck drivers).

bajafx4 wrote:I'll have plenty of leaves to use as browns. They're already starting to fall from some of my trees. I think winter is coming early this year.

Then full speed ahead and damn the torpedoes! Which there shouldn't be any of, actually.

Once it looks compost-y and doesn't smell any longer, it's fine for mulching. That works in. It'll take longer to get something you can dig in, but you may want to do that too.

Let the composting begin!!! I used a garden rake (you can see it in the picture) to lift enough weeds out of the water to fill four 32-gallon trash cans. How much seaweed do you think can safely be tilled into a 40x20 garden?

Also, normally I would be happy about not catching sheephead (Freshwater Drum), but we only caught two this weekend. Go figure, when I want to catch them, we only catch two... any other trip out we would have caught over a dozen.

If you fully compost the seaweed...all of it.

andy10917 wrote:
I've been tempted to do it with rinsed salt-water kelp.

I've often wondered about this -- we live near the beach (Pacific Ocean) and I could collect that stinky seaweed 'til the cows come home. Is it correct to say that all I would need to do before composting it is to rinse it and chop it? There is a lot of the bulbous kelp type -- is that better than the "shredded" finer-leaved seaweed? Or does it matter?

Sorry, bajafx4, for hijacking!

If I had the time to do this on a scale worthy of the effort, I would do a good rinse of a small amount (4 ozs?) and dry and chop it. Then I'd send it to a lab for tissue analysis. At that point I'd know what I'm getting that is good, and what I'm getting that is not-so-good (sodium salts?).

In your area (and mine) I think that rainfall is plentiful enough that you'd never build up enough Sodium salts to be concerned. It could be a great thing.

+1 Andy. Sodium buildup doesn't worry me too much, although (phun phact) they used to burn ocean seaweed to get sodium carbonate. I wouldn't go too overboard with it (pun intended), but as a component put down at 10 to 20 pounds per thousand per year it doesn't concern me in the slightest. Fifty, broken into multiple apps, wouldn't greatly concern me. A hundred...I wouldn't do that.

WARNING!!!
WARNING!!!
WARNING!!!

Fish and seaweed compost STINKS!!! Strangely enough it smells worse that rotten fish. If you attempt this, you may be adding vommit to your compost mix.

Kelp doesn't stink at all in my experience. Homemade fish fertilizer will stink badly. My experience with good commercial fish emulsion fertilizers is that they stink until they dry unless you try to apply them heavily - in which case they stink enough to drive you to the next County.

bajafx4, didn't someone say to cover it with leaves? And didn't you reply that you had plenty?

freyja5, I think you are overthinking it. Just pile it up and cover it with leaves. Shredding is too much work. Rinsing is optional. If you want to, do it. If not, I'm with the others in thinking there is not enough salt to be concerned about and possibly some of that salt is beneficial. Not all salt in the sea is sodium chloride.

FWIW, I routinely compost ~400 lbs of fish or fish scrap and 2 yds^3 of ramial wood chips in a pallet bin box, and have gotten it so tghere is negligible odor, just occasional slight ammonia. I also use shredded paper in immediatelyh around the fish scrap. The piles routinely heat up to 160F+ within a couple of days and can be turned after ~2 months (turning earlier vents significant ammonia). It CAN be done without odors even in a 4'x4' pile IF care is paid to fish layering and there is enough 1/4" carbon material available. Finished material will easily sift through a 1/4" mesh. I have ~10 yds now ready to go on the veggie garden or lawn. I'd be glad to provide any level of detail regarding fish composting.

Here is a thread on my learning experience: Click here for more information

By the way, our local easily accessible seaweed is eelgrass (Zostera marina). I find it works poorly as a compost ingredient, as it's too 'green' to combine with fish, and apparently not enough of a green to activate leaves or woodchips. It seems to sit in a pile an inordinately long time.
However, I spade in a 4"-6" layer into the veggie garden each fall, and it's pretty much 'gone' by spring. It also works wonderfully as a summertime mulch. I go through about 3-4 pickup loads /1000^2 ft of veggie garden each year. I've tried drying and shredding it in a leaf shredder and applying to the lawn, but it's too much of a PIA to do in quantity.