How the increased moisture in the ground during summer could lead to a floriferous autumn - plus, find out what else needs doing in the garden this week.

By Hannah Stephenson

As you look outside and despair at your soggy mass of potted petunias, drowning dahlias and other beleaguered bedding, there is light at the end of the tunnel.

Yes, the cool, wet weather of June and July has battered plants and made us all miserable this summer, but the increased moisture in the ground could lead to a floriferous autumn, says garden designer Chris Beardshaw, a regular panellist on BBC Radio 4's Gardeners' Question Time.

"The good news is that there's a lot of trees and shrubs and hedges which have benefited from the deluge," says Beardshaw, a Cheshire's Garden of Distinction ambassador and exhibitor at the recent show at RHS Tatton Park.

"Trees that had struggled with several dry springs and winters were starting to yellow early and suffer dieback in the crown and stunted growth. Now, they are very lush and there's plenty of growth.

"I've got acers and limes in the garden that have put on more growth this year than I've ever seen. Deep-rooted, woody and resilient specimens that are used to the temperature variations that we've had will do well."

Trunks will be full of moisture, taking in water-soluble nutrients and Beardshaw would be hesitant about feeding woody stock, although you'll still need to feed lawns, he advises.

"Put autumn food on lawns because shallower rooted plants have lost nutrients from their root zones. Anything that's shallow is going to be going yellow."

He reckons that anyone who's grown tomatoes, aubergines and cucumbers outside will struggle to get any sort of harvest because of the cooler weather and lack of insects to pollinate the flowers.

"We've seen a huge reduction in bees, butterflies, hoverflies and ladybirds which have been hit by two harsh winters and then a very wet summer. It's posing a threat to their population."

Faster growing crops such as lettuces should be fine if you can keep the explosion of slugs off them, he adds.

"For indoor tomatoes, it would be worth removing some of the leaves to expose the fruits because we haven't had high light levels, so the fruits won't ripen as quickly and the skins of tomatoes will go leathery."

If the foliage of conifers goes yellow, dig a small hole at the base of the plant and check the drainage is good enough, because they hate to be waterlogged.

On the plus side, the crowns of wild geraniums, astilbes and lupins have bulked up in the wet weather. Even if we don't get much flower, next year we'll benefit from the amount of root growth and leaf generation that those sorts of perennials have put on, he says.

"Roses have done very well, too. They don't mind wet ground and heavy soils, so there are some winners."

Summer annuals may have taken a hammering in the rain, but if you give them a good trim, then you may well see them bloom later, especially if there is any warmer weather on the way.

"Don't be afraid to trim them back because if we do get a burst of warmth they will have established themselves in the pots and if we give them a bit of a haircut and pinch out any faded flowers, as soon as the temperature increases you will have a massive potential of enthusiasm in the pot and the plant will react."

In the last few seasons we've had long, mild autumns, when annual bedding has come into its own.

"A sniff of warm bright weather towards the end of August could lead to late bedding displays, if you can keep the slugs off them."

Many plants will be flowering late, he predicts.

"We can expect a second flush of flowering on pears, rhododendrons and camellias, taking advantage of any warmer conditions in autumn.

"I just have a gardener's sniff that it's going to be a good autumn," he smiles, ever the optimist.

Best of the bunch - Thyme

Even if you don't have a herb garden, spare a pot or two for some different varieties of thyme, many of which are flowering at this time of year.

I have a lemon thyme, Thymus x citriodorus 'Silver Queen' in my rockery which is currently producing masses of lilac-pink flowers long after many of my other alpines have faded. Anyone who brushes past it will also pick up its wonderful lemon scent.

Thymes are also perfect for paths because many of them spread and grow almost flush with the ground and can withstand being stepped on from time to time.

A bushier plant which would suit a wall crevice is T. 'Fragrantissimus', which has an orange fragrance. Wild thyme (T. serpyllum) can also make an alternative lawn to grass, with its tiny dark green leaves and tiny lavender-pink flowers appearing in summer. It's particularly good for uneven surfaces where the soil is stony. Most thymes thrive in a well-drained soil in full sun.

Good enough to eat- Perfect peaches

You don't have to live in a Mediterranean climate to enjoy mouthwatering peaches in summer.

However, peaches do need a lot of care because of our climate. They can be grown in warm areas with the protection of a fairly high south-facing wall or fence but the flowers come early and the fruits need a lot of time to ripen. So it's probably best to start them off in a greenhouse and keep them there at flowering time to protect them from frost.

The trees need deep, well-drained but moisture-retentive slightly acid soil, with plenty of organic matter added. They should be planted in autumn and respond well to fan training.

They are self-pollinating so you can grow single trees, but, as they blossom before many insects appear, it's wise to hand pollinate them as well.

The easiest cultivars to grow in pots are compact or 'patio' cultivars, standard trees on high stems with a ball-like head. In late winter peach trees need to be sheltered to keep off the rain and stop peach leaf curl developing.

Three ways to... Make the most of colour.

1. Group hot colours close to your house and pastels further away to increase the feeling of space as the eye is drawn more slowly down the garden.

2. Blend contrasting colours with grey foliage plants, which will soften hot colours and draw different hues together.

3. Refer to a colour wheel, found in gardening books, to help you select plants on a colour basis. It will help identify complementary colours - pairs of diametrically opposed hues such as red and green, yellow and violet. Harmonising colours are adjacent hues which share a pigment, such as red-violet-blue, orange-yellow-green.

What to do this week

:: Harvest strawberries, cherries, summer-fruiting raspberries, currants and the earliest of the plums. Remember to harvest redcurrants and whitecurrants in bunches, still on the stalk - they will keep and taste better.

:: Stop cordon tomatoes by removing the main shoot. Look for the leaf that's above the fourth truss and cut it off here, to encourage the fruits to ripen by the end of the season.

:: Lift stunted potato plants to check the roots for the tiny nodules of potato cyst eelworm.

:: Tie in new growth on blackberries and hybrid berries.

:: Lift onions, shallots and garlic when ready. Plants should be harvested when the necks start to turn brown and papery, and bend over naturally.

:: Take cuttings of rosemary, bay and hyssop.

:: Feed containers and even tired border perennials, with a liquid tomato food each week to encourage them to bloom into the early autumn.

:: Don't cut off the flowerheads of ornamental grasses. These will provide winter interest.

:: Cut back hardy geraniums a little to remove tired leaves and encourage a new flush of growth.

:: Pinks and carnations can be propagated by layering.

:: Continue to remove blanket weed and duckweed from ponds using a net or rake. Pile the weed by the side of the pond for 24 hours to allow pond life to crawl back into the water and then put on the compost heap.