Seaweed products

Seaweed has been used as a soil improver for centuries, particularly in coastal areas. Seaweed contains several useful plant nutrients, including nitrogen, potassium, phosphate and magnesium. There are dried and liquidised forms available from garden centres and seaweed is a common additive to fertilisers, both organic and non-organic.

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Seaweed makes a good mulch for the vegetable garden. Image: ©

Quick facts

  • Seaweed is a good source of plant nutrients
  • Processed seaweed extracts are sold in dried or liquid form
  • Fresh seaweed can be dug into the soil like manure
  • Calcified seaweed makes the soil more alkaline

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