New patio plants on trial

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 easy-care 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 & 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 water-retaining crystals and slow-release 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. Sign up to Which? for a one-month trial for £1 to access its product reviews, test scores and Best Buy or Don’t Buy ratings. For more information, visit www.which.co.uk/signup

BEST OF THE BUNCH - Primrose

Widely available in garden centres at this time of year in a mass of colours ranging from white to deep purple, primroses add a wealth of colour to spring containers and at the front of borders.

They’re from the Primula genus, which comprises about 400 types, some evergreen, enjoying sun or partial shade in deep, moist but well-drained soil, rich in organic matter.

Good varieties include Primula ‘Wanda’, which produces claret flowers above clumps of toothy leaves, and P. vulgaris ‘Double Sulphur’, a vigorous evergreen perennial with funnel-shaped double pale yellow flowers.

There are other taller types including Primula denticulata, a herbaceous perennial which grows to around 45cm (18in) and produces lollypop rosettes of flowers in shades from white to lilac.

THREE WAYS TO... Make the most of edible flowers

1. Garnish fruit salads with rose petals, or simply scatter them on tables.

2. Sprinkle the nutty-flavoured flowers of polyanthus over salads.

3. Use the pretty petals of chive flowers, which have a mild onion flavour, to add to salads. Leave the heads whole if you just want to decorate a dish.

WHAT TO DO THIS WEEK

:: Sow seeds of summer bedding, herbs, lilies, trees, shrubs and some vegetables. Many will benefit from being started off under glass.

:: Place supports in position around border perennials that need staking, so the plants will grow through them and hide them.

:: Start removing sideshoots and pinching out tendrils if growing sweet peas on a cordon.

:: Hard prune shrubs, such as buddleia, that produce their best show on vigorous new wood.

:: Use brassica collars to protect cabbages and cauliflowers from cabbage root fly, and erect plastic screens in the vegetable garden to deter carrot fly.