SUMMER pots should be a riot of colour, ideally with flowers that bloom into autumn. Hannah Stephenson looks at trials of new patio plants to find out which will be worth growing.

As summer beckons, many gardeners will now be deciding which patio plants to feature in their scheme, but it’s a difficult job as there’s so much choice and plants can vary greatly in quality.

The perfect summer container plant should be long-flowering and disease-resistant. But many simply don’t do that job.

To save you some of the bother of trial and error, Which?

Gardening, the Consumers’ Association magazine, has now produced a report after growing more than 35 new varieties suited to containers or baskets before they were released to the public.

The plants, which were bought as plugs or young plugs last April, were grown in good quality container compost with added slow-release fertiliser.

The planted containers were kept in polytunnels until all risk of frost had passed and then brought out in June, watered and deadheaded as required.

Among the pick of the crop were Osteospermum Serenity series (Mr Fothergill’s; Unwins), with its soft pastel or terracotta-toned flowers that mature to a deeper, warmer shade, and the Nemesia Lady series, a deliciously scented variety which looked great in mixed plantings with Calibrachoa ‘Can-Can Rose Star’ and Pelargonium ‘Caliente Pink’.

The white Nemesia ‘Sweet Lady’ was the longest flowering of three highly scented varieties and still looked good in September.

For those interested in new basket plants, winners included Petunia ‘Sanguna Atomic Blue’, which brings drama to any arrangement, with its dark throated flowers with dark veins leading to a deep-mauve colour of the rounded petals.

It carried on flowering when other plants were waning, trailed well and didn’t suffer from having all the flowers at the bottom of a curtain of green growth (B&Q; The Garden Centre Group; Homebase).

Last year trialists grew several varieties of sunpatiens (a New Guinea hybrid), which all performed admirably and showed no signs of being affected.

The Sunpatiens Compact series were extremely vigorous, tolerant of both sun and shade and produced beautiful, vibrant flowers which required only a little tidying to stay looking pristine.