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Best Buy composts for containers

By Adele Dyer

You need a great compost to grow pots of bedding and bumper crops of veg. Our tests find the best composts for pots and containers.

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The best composts that we recommend here are proven to grow plants that are covered in flowers non-stop throughout the summer and large, healthy vegetables. 

Best compost for containers

Pots and hanging baskets filled with flowers are the perfect way to brighten up your patio. Many types of veg are also happy to be grown in containers, so your patio can be productive as well as beautiful. Our tests over the years have shown us that choosing the right compost is vital as they vary widely. 

You can't tell a good compost by looking at it, and big-name brands are not always a sure bet. We test compost every year to find the best ones available for pots and containers. 

Last summer, we grew 12 pots of Osteospermum 'Orange Symphony' and Potato 'Sarpo Axona'. We planted them in May and grew them on outside until early October. The plants were judged by an independent assessor, an expert in growing media, in July, August and October, for health, rate of growth, leaf colour and how well they flowered. 

See how all the composts scored by looking at the full results table and see which were Don't Buy composts for containers. 

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Compost Our verdict Osteospermum Potatoes Score
Compost non-member logo M **** ***** 75%

Best Buy compost: Best peat-free

Peat content: 0%

Price per litre: 12p

This peat-free compost is mostly coir with a little vermiculite. Coir is made from milled coconut husks and behaves a little differently to other composts. The surface can dry out, while it can still be very wet further down, so it's important to be careful with your watering. 

All our pots grew slowly at first until the controlled-release fertiliser started to work. By mid-summer the bedding plants were impressive and the potato crop was the heaviest on test. 

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Compost non-member logo M ***** **** 75%

Best Buy compost: Best peat-based compost on test

Peat content: 70%

This compost isn't cheap, but it's currently a Best Buy for sowing seeds. It was a Best Buy last year for sowing seeds and growing young plants, and was recommended for containers. 

It excelled at growing large bedding plants that were covered in flowers for months on end. The potatoes were smooth skinned, but mostly medium sized. 

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Compost non-member logo M ***** **** 71%

Best Buy compost: fantastic for bedding plants

Peat content: 0%

This peat-free compost is a Best Buy for containers for the third year running, and has done well in our tests for sowing seeds and growing-on young plants. It doesn't include green compost, which is often made from municipal green waste and leads to variable quality in some peat-free composts. 

The bedding plants romped away early in the season and we got a heavy crop of good-looking potatoes. 

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Compost non-member logo M **** **** 70%

Recommended compost: large potato crop

Peat content: 0%

This peat-free compost was a Best Buy for sowing seeds in our recent trials and scored well for young plants, too. 

The osteospermums flowered well from June onwards and looked good all through summer. The crop of potatoes was substantial and included several pots of mainly baking-sized potatoes. 

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Compost non-member logo M **** **** 70%

Recommended compost: extra fertiliser

Peat content: 40-70%

This new compost is largely made from peat, with wood fibre and bark. The makers are a little cagey on how much peat it contains, telling us it is between 40% and 70%. It also contains controlled-release fertiliser and this lasted well through the four months of our trial. 

The osteospermums looked good for months and we harvested a good crop of medium-sized potatoes with lovely smooth skins. 

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Compost non-member logo M **** **** 70%

Recommended compost: great-value option

Peat content: 70%

This compost is a great budget option. It has a high peat content and scored well in our trial of composts for seeds and young plants, although it missed out on being named a Best Buy. 

It grew excellent bedding plants that got off to a flying start early in the year. The potatoes were a good size and excellent quality, although the yield was slightly lower than some other composts. 

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