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1 October 2020

Best composts for sowing seeds

Seeds are self-contained packages that have everything inside them to germinate and start to grow. They just need fine, well-drained compost. 
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Adele Dyer

A great compost for sowing seeds should have a fine texture that will surround the seeds with everything they need for strong, healthy growth. 

It should also have the right balance of nutrients to grow a range of plants at this early stage of their development. The worst however, will be prone to water logs and will be full of lumps. 

Make sure your seeds get off to the best start and avoid growing lack-lustre plants and veg by checking out the full table of results below. 

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Best composts for sowing seeds

Which? Best Buy composts for sowing seeds

Not found the right product for you? Browse all our compost reviews

The best peat-free composts for sowing seeds

This year, the best peat-free options for seed sowing are the two Melcourt SylvaGrow composts. Their scores show the germination was good and the seedlings were healthy, but weren’t quite as strong as our Best Buy composts.   

Things to look for when buying compost for sowing seeds

Here are two useful features to look for when buying your compost:

  • Balanced nutrients - the right amount of different ingredients to grow a range of plants at this early stage of development.
  • Good structure - will encourage strong root growth.  

For more advice on choosing the best compost for you, head to our compost buying guide.

Why Which? compost reviews are better

Which? is independent and doesn't accept advertising or freebies, so you can trust our reviews to give you the full, honest and impartial truth about a product.

Before testing we send out secret shoppers to buy all our compost so we know we are getting the same product as you. 

We then sow seeds of basil 'Puck' and Petunia 'Express Rose', with 25 seeds of each in quarter-size trays. 

When the majority of seedlings are at the first two true-leaf stage, we count the number of seeds that have germinated and rate the seedlings for size and vigour. 

To find out more, head to how we test compost. Alternatively, browse all our compost reviews.