Seaweed in the garden

Composting is great fun and any wacky ‘ingredient’ I see, I tend to scoop up in the hopes of improving my heap. And that includes seaweed, nature’s fertilizer, which I gathered on a recent trip to the beach.

Here are five uses for my slimy pile…

1. Use as a mulch.

Many seaside gardeners wash seaweed (taken from the beach, not the rocks) and then spread it round their plants to help keep water in and protect plants. If you do it over the summer you can leaving it to rot into the soil over the winter. It’s great at retaining nutrients, so you can put that goodness back into the soil. You can read more about mulching on the eartheasy blog.

2. Make a plant tea

Seaweed is great at retaining nutrients, so why not let all your plants take advantage? Give the weed an initial rinse if you’re concerned about salt or pollution, then let it soak for 3 weeks in a bucket of water. Dilute one cup of the resulting ‘tea’ to one bucket of water, and use it to feed your urban farm. You’ll want to cover the bucket while it’s ‘brewing’ as this is the stinkiest cuppa you’ll ever go near. Find out more about the nutrients it contains on the RHS website.

3. Add it to the compost

The easiest thing to do is to simply add your seaweed to the compost heap.
Seaweed rots quickly, adding nutrients to your compost and encouraging other matter to break down. It’s particularly good for clay soils as it contains a chemical that stops soil clumping. But it can become slimy so make sure you mix it with some fibrous material like tree prunings or scrunched up paper.

4. Burn it

If you’re feeling ambitious, seaweed ash apparently contains an even more concentrated source of potash, which your plants will love.  Gently dig the ash in to the top of the soil during the growing season.

5. Make a plant care spray

You can also use your seaweed tea as a spray to help sick plants – such as those who’ve succumbed to frost damage, as you can see Monty Don doing.  The spray will also send insects running.

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