How to Compost With Kelp


Common to the Pacific Ocean, kelp is a seaweed variety that is nutrient rich and has an array of uses, from tasty seaweed salads at sushi restaurants to landscaping compost. Kelp is most known in gardening for keeping soil aerated and nutrient hardy, so it works especially well with flowers, fruits, vegetables and herbs. When composting kelp, there are some key things to keep in mind.

Step 1

Harvest kelp straight from the beach if you live near the ocean, storing it in large plastic sealable bags. You can also purchase raw kelp from organic garden suppliers.

Step 2

Layer the kelp in a 50-gallon drum, making sure to fill it no more than halfway full.

Step 3

Fill the drum with water. Put the lid onto the container to make it airtight.

Step 4

Let the drums with water and kelp sit for about two months in a dry, cool place to compost. Once composting is complete, it will resemble a brown tea-like liquid with pieces of brown debris.

Step 5

Scoop out 1 cup of the kelp water compost and put it in a plastic gallon jug. Fill the rest of the jug with water to dilute the mixture.

Step 6

Water your plants with the mixture, or put it in a sprayer and spray the plants. Apply the kelp compost tea to your landscape about twice per year, once in spring and once in fall.

Things You'll Need

  • Large plastic bags or a kelp source
  • 50-gallon drum with airtight lid
  • Plastic 1-gallon container
  • Spray bottle


  • PlanTea: Compost Happens
  • Backwoods Home: Make Your Own Compost
Keywords: composting kelp, composting seaweed tea, what to compost, make kelp tea

About this Author

Lauren Wise has more than eight years' experience as a writer, editor, copywriter and columnist. She specializes in food, wine, music and pop culture. Her writing has appeared in various magazines, including "Runway," "A2Z," "Scottsdale Luxury Living" and "True West." Wise holds a Bachelor of Arts in journalism from Arizona State University.