When is 'organic' not 'organic'?

Which? Gardening magazine research reveals that organic labelling on compost is not what it seems. Those trying to garden without chemicals could be getting fooled into buying compost that's not suitable for organic gardening.

If you're an organic gardener or simply want to buy organic compost, always carefully check the label of any product you buy. Our research has discovered that, as compost contains 'organic matter' ie decaying plant or animal material, it can be labelled 'organic' but still contain constituent parts that aren't suitable for organic gardening.

Always look for a label that says 'certified organic' to make sure that any product has gone through the organic certification process.

Then, head straight to our best compost reviews to find the top performer for your seeds, young plants, pots and veg.

How do you know compost is organic?

A representative from Garden Organic - a charity dedicated to promoting organic gardening - told us: 'You can often find out if you're happy to use a product by looking at its ingredients and production methods.

If in doubt, we recommend people look for appropriate organic certification, such as the Organic Farmers and Growers (OF&G) or Soil Association logos, to ensure the contents are independently certified as organic.'

Talk to other gardeners about this topic on the Which? Gardening Facebook group.

Which are the best composts to buy?

Each year, Which? Gardening magazine tests composts for sowing seeds, raising young plants and growing plants in containers. We also test growing bags, which are great for indoor veg, such as tomatoes and cucumbers.

We have more than 30 years of experience testing composts, so we know just how much difference there is between a Don't Buy and a Best Buy.

All compost looks exactly the same in the shop so the only way to know if it's good or bad is to look at our compost test results.

• We send secret shoppers to buy our composts, so we can be sure we're buying the same compost that you are.
• Our shoppers live in four different parts of the UK, so we're able to see if there is any variation between batches.
• We carry out our tests at a well-respected horticultural institute that runs trials for scientists and horticultural industry bodies.
• The experts there have the knowledge and expertise to ensure our trials are conducted using the best growing techniques, so we know that any differences in performance are down to the compost itself.

We publish the results of our trials in the Jan/Feb, March and April issues of Which? Gardening magazine - subscribe by calling 029 2267 0000 or sign up online.