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Best Buy composts for raising young plants

By Adele Dyer

Seedlings and small plug plants need a compost that's low in nutrients to start with, but it should be able to keep the plants well fed as they grow.

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Our Best Buy composts for young plants consistently gave seedlings and plug plants the right conditions to put on impressive growth. 

Best composts for raising young plants

Young plants, such as seedlings and plug plants, need a compost that will support their growth. This means one that is not so high in fertiliser that it burns their roots while they are small, but which is able to keep them well supplied with nutrients to fuel their rapid growth. It's also vital that the compost can hold enough water to keep the plants from drying out, which will seriously impede their growth. At the same time, the compost shouldn't be so wet that the plants rot off. 

We chose to grow pepper 'Arianne' in our young plants trial. Before the trial started, this was germinated from seed and grown on to the two true-leaf stage - the point at which you would usually repot the seedlings. We also grew fuchsia 'Shadowdancer Amelie', bought as plug plants grown from seed by a specialist nursery. 

After six weeks, we judged both the young plants on how vigorous they were, which includes looking at size, leaf colour, and whether the plants are stocky and strong or long and straggly. We also noted how well the fuchsias were flowering. 

See how all the composts scored by looking at the full results table. 

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Compost Our verdict Young pepper plants Young fuchsia plants Score
Compost non-member logo
90%

Strong and healthy plants

Peat content: 70%

This compost is formulated specifically for potting up plants. It contains a slow-release fertiliser and seemed to give our plants a boost towards the end of the trail. 

Almost all of the composts in our test contain some fertiliser, which is designed to feed the plants for the first few weeks, but in most other cases this was running out by the end of the trial. 

Our pepper seedlings and fuchsia plugs all grew into large plants with dark-green leaves, and the fuchsias were covered in flowers. 

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Compost non-member logo
87%

Fantastic fuchsias

Peat content: 58%

Price per litre: 21p

The peppers grown in this compost were among the best in the trial. The sizable plants were robust and had excellent leaf colour. The fuchsias were outstanding - the best on all criteria: flowering, size, leaf colour and health. 

This multipurpose compost has been a Best Buy for sowing seeds and raising young plants several times in the last few years. However, this time our petunias didn't germinate as well as in other composts, which stopped it being a Best Buy for sowing seeds. 

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