Property: Time to sell it with flowers: The wisteria's wonderful, rhododendrons are a riot, so spring into action says Anne Spackman

Anyone who is considering moving house in the next 12 months should take a stroll around the garden this weekend. The wisteria and lilac are in bloom, the hawthorn is heavy with blossom, the rhododendrons are resplendent. Doesn't it all look wonderful? A complete transformation from the bleak, bare days of winter when the trees fail to hide the new bungalow at the end of the garden. It is time to call in a photographer, even if your move is many months away.

However gorgeous the interior of your house, it is the picture of the outside that prospective buyers will see when they visit the estate agent. The agent's hardest job is to persuade people that your house is worth a visit. If it looks great in the picture, the job is half done.

Over the past few years buyers have generally been forced by circumstance to sell, so the traditional seasons of the housing market all but disappeared, particularly in the cities. Now, they are back, and spring has come in with something of the old-style fanfare.

More than 20 potential buyers went to see the Old Boathouse at Lower Radley in Oxfordshire in its first few days on the market. The house was built in the 19th century as the dry boathouse for nearby Radley College. It sits in two acres of secluded gardens with woodland and a pond, leading down to the river, where it has 230 yards of Thames frontage and a slipway. It is up for sale with a guide price of pounds 275,000.

'We decided to launch that house in particular on the market now, because its position is so much part of its value,' said Celia Beor-Roberts of Knight Frank & Rutley in Oxford. 'We've waited about six weeks for the time to be right. If the outside is a big selling point, you don't want to see it for five minutes in the rain in the winter. In an ideal world, you would always take the pictures in the spring.'

However, she thinks the upturn in business in May is as much to do with freshness and newness and the uplifting feeling of the first warm sun as it is with gardens. Andrew Ireland, of John D Wood in Wimbledon, agrees. 'If it were just a case of the garden looking better, you could go out and spend a few hundred pounds on winter- flowering shrubs. It's the fact that we all feel more content, more optimistic.'

The May factor is also apparent down the road in leafy Sheen, where Sue Porter of Dixon Porter has just put 40 Roehampton Gate on the market for pounds 650,000. It's a five-bedroom 1930s house with a good garden by Richmond Park. 'At this time of year, houses close to parks or commons receive a considerable boost in demand,' she said. 'The attraction of being close to large open spaces is obviously felt that more strongly while the sun is shining and the evenings are lighter.'

One of her customers has spent the past two months preparing her garden for viewers, having decided to put the house on the market once the wisteria was out. In another instance, where Sue Dixon knew for 12 months that the owner planned to sell this year, she took pictures of a particularly stunning rare tree last autumn when it was at its best.

Christopher Lacy of Savills in Salisbury has also postponed a launch to coincide with spring. West Walk House is a new property in the otherwise ancient Cathedral Close. It has lawns sweeping down to a 75-yard frontage on the river Avon, with views across to the water meadows beyond. 'In Cathedral Close the environment is of a special quality,' Mr Lacy said. 'It has a river setting, which is a particularly attractive commodity.

'The advice from us in December was that, if you could wait, the chances of securing a purchaser would be better in the spring and summer. It seems that people in London who want to buy a house in the country are far more tempted to do it at this time of year.'

In Henley, his colleague John Harris stressed the importance of timing for pictures. 'The amount of money you spend on proper photographs is a tiny proportion of the property's value,' he said. 'If a buyer gets details of eight or 10 properties in a week, and decides to spend a weekend viewing, you have to make sure yours is one of the four he or she goes to see.

'I am putting a house on the market this week, and the photos were done last August. The owners weren't sure when they were going to go, but they took advice and got the pictures ready early.'

In Scotland, May is often the first month for buyers to look around sporting estates, where the land is crucial to the purchase. Andrew Spencer Nairn of Strutt & Parker in Edinburgh said it was simply not practical to take viewers around the Highlands when half of it was under snow.

But if this is the best moment for sellers, does it mean it is the worst for buyers? Are they being suckered into paying some thousands of pounds more for clematis and a few green leaves?

Not directly, it seems. There is a healthier market in spring than at any other time, which means more buyers and more houses from which to choose. The line from agents is that spring makes a house easier to sell, but that it doesn't make it worth any more money.

The one factor most likely to push up the price of a house is competition from buyers. And although spring has brought quite a lot more houses on to the market in some areas, such as Oxfordshire and Gloucestershire, there is still a dearth of property in others, particularly in London and Surrey.

The property market is not like the market for convertible cars, where it pays to wait until November. Instead, the really clever buyer will let others compete for the pretty house up the road, and buy its ugly sister for less. Then it's straight down to the nursery and on with the gardening gloves.

(Photograph omitted)