WONDERING what to put in your patio containers this summer? My pansies and violas are looking so forlorn I’m already thinking I’ll ditch them in favour of some higher achievers in this unpredictable British weather.

Help is at hand, in the form of a new trial from Which? Gardening, the Consumers’ Association magazine, which last summer tested 47 new varieties of plants for containers or hanging baskets, bought as plugs or young plants in April and then planted into suitable containers.

The young plants were grown under cover until the threat of frost had gone and planted in container compost with added slow-release fertiliser.

The trial found that the easycare plants which produced plenty of blooms included Argyranthemum ‘Yellow Empire’ (Mr Fothergill’s), a classic marguerite with bright yellow daisy-like flowers which – with some deadheading – produced masses of flowers throughout the summer.

Another winner, which combined well with the marguerites, was Bacopa ‘Atlas’ (Dobies, Mr Fothergill’s, Suttons), a blue and white variety which makes a background for blowsier plants in a mixed planting. This variety also produces unusually large flowers, almost 2cm across, and trails brilliantly. Those trialled flowered continuously for 18 weeks.

Diascia ‘Blue Belle’ (Plants By Post, J Parker’s), a new variety launched at the Chelsea Flower Show last year, cascaded over the sides of the basket and didn’t need deadheading, while Petunia ‘Queen Bee’ (Spalding Plant and Bulb Company) proved a vigorous grower, producing a plentiful mix of yellow and deep purple blooms and a succession of flowers despite heavy rain.

Among the best rain-tolerant plants tested was the Pelargonium ‘Pacific Black Knight’ (Dobies, Suttons), an ivy-leaved variety with velvety flowers, which continued to flower until the trial ended in October.

If you want to grow flowers for cutting, have a go with Dianthus ‘Green Trick’, an unusual hybrid sweet William with large, fuzzy green heads, which last at least 10 days in a vase.

There are ways to help your patio plants along. Use big pots, if you can, so there are more nutrients for the plants to root out, and the more compost there is, the more water is retained.

Water the compost thoroughly rather than little and often, to allow the water to seep deep into the pot and encourage healthy root growth, rather than just wetting the surface.

Make sure your compost doesn’t dry out because it can be difficult to rehydrate.If you are using hanging baskets or smaller pots, they may recover if you dunk the base in a bucket of water for a while, to allow the water to soak the compost from below.

It’s also worth adding waterretaining crystals and slowrelease fertiliser to the compost before planting, to help retain moisture and avoid the need for regular liquid feeds throughout the summer.

And if it rains – which knowing our inclement weather, it is bound to do – carry out a regular slug patrol on your young plants and pick them off by hand, to save young shoots and leaves from being eaten.

  •  The full report is in the April edition of Which? Gardening magazine. For more information, visit which.co.uk/signup.