My mom Jo Ann taught me how to be an artist, a gardener, and an independent & curious thinker. She has a great city garden in Quincy, MA where she has found creative ways to produce loads of veggies, herbs, flowers and compost within unusual spaces, all while balancing her time-consuming career and constant world traveling. She learned this really cool seaweed trick from my great-grandmother, so I asked her to share it with you as we all prepare for the spring.
---------------------------------------------------------------------------------------
See weeds? Use Seaweed!
As a young girl, I remember spending time with my grandmother on Cape Cod. She had the most amazing vegetable garden, and spending time with her, my job was to pull weeds. Often, we would walk down to the nearby beach and collect seaweed. My grandmother would use the seaweed as a mulch to keep the weeds under control. She would spread it out around the plants, both flowers and vegetables, and have very little weeds to tend.
Now, I am living around the Boston area near the harbor and I am able to walk to the beach. I remember my grandmother using the seaweed in the garden, so I decided to try it out myself.
Seaweed is really not a weed at all. It is a multi-cellular marine microalgae. It is a plant, but instead of having roots, stems and leaves, it has holdfasts, stipes and blades. There are over 250 species of seaweed in the Northern New England area, and there are three kinds of seaweeds:
- Green Algae (Chlorophyta) lives in shallow waters along the shore
- Brown Algae (Phaeophyta) lives in sub tidal zones
- Red Algae (Rhodophyta) lives in deeper waters
All seaweeds attach themselves to the ocean floor, or onto other bases like rocks and shells. They create habitats for all sorts of sea creatures and provide food for others.
Having a vegetable garden can be hard work. You have to dig the earth, mix in nutrients, plant seeds and water daily. Once that is done, you can stand back and watch it grow. But, undoubtedly you will also watch the weeds grow. The task of pulling weeds is a daunting one. This is where the seaweed comes in.
I find it easiest to collect seaweed when the tides are moving out. Try to collect only those seeweeds that are not attached to rocks, so as not to disturb the ecosystem that is living among the seaweed. If you do find seaweed that is attached to rocks, you can use that seaweed, but don't take all the seaweed from one area so as not to leave the marine life without a place to live. You will find that when the tide is rolling in, it brings those seaweeds that are not attached and, when the tide rolls out, it leaves behind a wealth of pickings.
The equipment I use to collect the seaweed are simple things I have around the house. I will usually drive my car down to the beach even though it's close enough to walk, because wet seaweed is heavy and difficult to carry. I like using the big tarp-like Ikea bags to transport the seaweed home. This keeps my car fairly clean. I have two buckets that I will walk down the sand with, fill down by the surf, and return to my car to empty into the IKEA bag. Usually three or four trips will fill the bag.
When I get home, I spread out the seaweed in the yard. I like to spread it out near my composter (there are lots of weeds growing around it). There is also honeysuckle growing along that side of the yard, so it keeps the air smelling nice. You should not find seaweed to be fishy smelling; since the seaweed you collected does not have marine creatures dead in it, you wont get the bacteria breakdown that causes that smell.
I like to rinse off the seaweed with the hose. This will rinse off the sand, and some of the salt. I have read that some people just use the seaweed without rinsing; it adds sand to heavy soil, and many nutrients.
I let the seaweed dry out for a few days before I spread it around my plants. During that time I will rake and mix it every day, so that most of it dries out. What I like is that the seaweed will absorb water and keep the plants moist as well. So, you will often see the seaweed dry out, then rehydrate after rain or a good soak.
As the seaweed dries out, you will have to add more seaweed to the mulch layer, since it shrinks when dry. When it does dry out, this may allow weeds to pop through the mulch layer. But, I found that those weeds are very few and are easy to pull with little effort.
Here are some other ways I use seaweed:
- To layer in the compost heap
- To repels slugs and other pests with the natural salt content
- Made into a tea and used around the yard, it will repel molds and fungus
- Working dried seaweed deeper into the garden soil to add nutrients for next years crop
If you have a garden, and have access to the ocean, you will find that mulching with seaweed will help keep your plants moist and will keep the weeds and pests at bay.
--Jo Ann Fugazzotto
Jo Ann Fugazzotto is a gardener, FarmTina's mom, and an oncology NP. She rides her bike to work every day, loves to take her Boston Terrier for walks along the beach and through the woods, and has traveled extensively around every continent except Antarctica. Lately she's been into orchids, craft beers, and hunting down antique furniture.
JoAnn has contributed valuable materials to the FarmTina project (such as the palet garden supplies), and even more valuable knowledge and support.

I've always suspected seaweed to be useful, this was really very informative. Sounds like you have got your garden under control, can't wait to try this myself! :)
Posted by: Skye Dawnbreaker | Sunday, January 15, 2012 at 07:21 AM