I've been to every Hampton Court Palace Flower Show since the event was born in 1990, and found each better than the one before. This year's hasn't happened yet it opens next week but I know already it will outclass all its 14 predecessors.

There'll be more space, more to see, more to do, more to eat and drink in short, more of everything that makes this show so irresistible.

Hitherto it has occupied 25 acres. This time it will have 31, thanks to the restoration of the Long Water Avenue, created for King Charles II in the 1660s, and the replacement of more than 500 of its decaying lime trees.

The project, only just completed, has opened up a further six acres, enabling the Royal Horticultural Society (RHS) to plan a new and much-improved layout. For example, many of the show and water gardens, and the Country Living pavilion, will be relocated in the new space, and a fourth pontoon will be placed across the Long Water to enable easier movement around the larger site.

"The Long Water avenue will be a leisure area, offering peaceful relaxation, stunning views of the palace and an interesting choice of cafs and bars," said the show's manager, Eddie Farrell.

"The show gardens will follow a single route, making them much easier to find. And all will have a larger viewing space in front of them."

There will be 16 refreshment venues four more than previously with new ideas such as a tapas bar, deli bar and a cheese and wine servery. This, as Eddie explained, is because good refreshment and rest facilities are essential if one is to get maximum enjoyment from an event which draws a total of 185,000 visitors, has more than 700 exhibitors, and is the largest annual flower show in the world.

So much for bodily comforts. What of the show's visual impact? As usual, the star exhibit, and the one most people visit first, is the Daily Mail Pavilion. This year it has a waterside theme and, also as usual, its centrepiece is a replica of a real-life country cottage that can be yours if you win a competition.

It has been painstakingly reproduced by Effigy, the company founded in 1988 by Damon Wood, of Walton. This is the 10th Daily Mail Pavilion cottage he and his team have created and, as in previous years, he visited the real thing and took measurements before creating an exact facsimile in his workshops.

"It's a typical chocolate-box sort of house in rural Dorset," said Damon. "We built it in 18 timber sections, then loaded them on to a lorry to assemble on site. It will have taken 12 people three months to get it completed."

The thatched roof is genuine, assembled by skilled thatchers. But the sandstone walls though you'd never guess it are moulded plastic.

Usually, there are four show gardens in the pavilion. This time there will be five, all linked by water. The quintet will begin in a mountain garden designed by Tim Sharples. He and his wife Kate launched their Cedar Nursery at Cobham in 1988, and he has been designing gardens for the Hampton Court show since its inception in 1990.

His latest, the fourth and most challenging he has designed for the Daily Mail Pavilion, features a stream rising from its source and tumbling down sandstone rocks to a deep pool below. A gravel path leads round the changing levels of the garden, and plants include some of the finest acers to be seen in the UK.

The next two pavilion gardens have been designed by Sarah Eberle, who last year won the show's highest award, the Tudor Rose.

One has the stream flowing over a slate bed. In the other it meanders through a country garden. The fourth garden, by Sally Court, includes a lawn sloping down to the waterside. The fifth, by Rosy Hardy, shows the stream flowing gently through a cottage garden full of beautiful perennials, trees and well-stocked vegetable plots.

A new marquee, the Growing and Showing Marquee, will make its debut this year. From July 6 to 8 it will house the Floral Art Competition. Then, for the final two days on July 10 and 11, it will be given over to fruit and vegetables. And another interesting new facet it will feature a competition open to all amateurs who grow fruit, veg or herbs in allotments or domestic gardens. They can choose from dozens of classes, and there will be cash prizes for the first, second and third winners in each.

What a golden opportunity for amateurs to see their produce displayed at a world class show.

The closing date for entry forms is June 28. For more information, contact the RHS Shows Dept on 020 7630 7422, or send a self-addressed A5 envelope, marked Fruit and vegetable competition HCPFS to Shows Dept, RHS, 80 Vincent Square, London SW1P 2PE. But hurry.

Alongside the competition, the Trials Dept at the RHS at Wisley will be displaying its finest mid-summer produce, including a brand-new runner bean, Wisley Magic, as part of the RHS Bicentenary Plant Collection.

The RHS Advisory Service will also be on hand to give expert advice on everything to do with growing your own produce.

Produce will be much in evidence in the rest of the show as well. Ornamental fruit and veg, together with edible herbs and flowers, are back in vogue, and several show gardens will present a new take on the traditional kitchen plot.

We all keenly look forward to the display gardens, and this year there will be 53 of them more than we've ever seen before.

All will be superb in their very different ways (they wouldn't have been picked by the selection panel if they weren't), but I'm specially interested in exhibitors from our local area.

This year they will include the irrepressible Mark Turner, who really does have fairies at the bottom of his garden in Teddington. Some of them he sculpts in bronze for sale via his garden sculpture company, Enchanted Ltd.

The rest, he swears, are the genuine, magic article, not always visible to anyone but him. He says both sorts were present in his show garden which won a silver medal last year. And both sorts will be on hand this year, when he hopes to win gold with his fantasy, Life is But a Dream.

This will be a wild place with a gothic tower, cascades of water and, in his words, "a bridge between this world and other magical realms". There will be plants too, of course, all grown in Teddington by him and his wife, Tulin.

Jonathan Gittins, of Sutton, is a lighting designer and electrical consultant by profession, and gardens only as an occasional spare-time amateur. But that hasn't deterred him and his Norwegian girlfriend, Torunn Saksvikronning, from making their show debut with a garden unlike anything ever seen at Hampton Court before. Conceived as a garden at night, it will be enclosed in a dark shed, illuminated by the latest LED techniques, and viewed through slots in the outside wall. I could say more, but don't want to spoil the surprise!

The Garden Gang, 20 people with learning difficulties from The Avenue Centre in Teddington, have grown 2,000 plants in the Italian national colours of red, green and blue for their innovative Italia Galleri, the first two-tier garden ever seen at the show. It can be viewed at ground level, or from a balcony 8ft high running round the perimeter, and has been designed by David Brum, Richmond Council's senior landscape officer.

The gang was established in 1991 as a commercial landscaping enterprise under the umbrella of Richmond Social Services. Led by David Brum, it has built three previous gardens for the show, and won medals each time, including a gold.

Janette Dollamore of Cobham was a 40-something academic librarian when she embarked on a mid-life career change and became a garden designer. She was on the Merrist Wood College diploma course in garden design when she met Jo Ward-Ellison, a 40-something market researcher, who had also decided to change career.

Now the pair have teamed up with a third friend, Matt Morgan, to produce their Hampton Court showpiece. They have called it the Triquetra Garden because, as Janette explained, "three of us are doing it, and it represents the three planes of existence: physical, spiritual and mental". It's a courtyard concept, built of natural stone, slate and granite, with a water feature in the centre.

Steve Gelly and Nigel Boardman launched their family-run Boardman Gelly business in Wimbledon 15 years ago. Now based in Redhill, they have won medals at Hampton Court for the past 10 years. But the gold, the one every exhibitor aspires to, has eluded them. They hope to achieve it this time with Two Point Four Children, a townhouse garden designed to entice children away from television and computer screens and into the fresh air. It has a play tower and a slide down into a sandpit (with a sail over it to protect against sunburn).The raised decking has a secret den beneath it, and across the lawn is a patio area for adults.

Steve, with two children, and Nigel, with three, know exactly what youngsters like. That's why they were chosen to create eight gardens for schools in the Croydon area part of a Government campaign to encourage children to lose weight with outdoor exercise.

A star of the show is usually Jane Mooney, the brilliantly original and modernistic young landscape architect who runs her own design firm at Thames Ditton, and is one of the few to have won the show's highest honour, the Tudor Rose Award. This was for her Mercedes Benz garden in 2002 and this year Mercedes has commissioned her for the third time.

The result is Movement and Style, in which a striking combination of steel and stone is used to create a multi-functional garden for relaxation, entertainment and dining.

But Jane has had to forego some of the heavier physical demands of the show as her first baby is due in August.

Squire's, the horticulture firm founded in Twickenham by David Squire nearly 70 years ago, has been exhibiting at the show since it began, and always wins medals. This year's exhibit is an exquisite miniature garden in the floral marquee, with a sunken circular lawn, a semicircular terrace and arbour, and a romantic blend of roses, perennials and annuals. As in previous shows, it has been designed by Colin Squire and planted by Jim Phillips, who retired after 25 years with the company, but returns each year to mastermind its floral exhibit.

Sky weather presenter Hazel Murray unexpectedly fell in love with gardening after moving to a flat in Twickenham in 1995.

"Though the flat is at the top of the house, the garden below is mine," she explained.

A year later she and her partner, Dominic, took two nearby allotment strips and planted their own vineyeard. Since then, their 100 vines have matured and now yield around three bottles each a year. Meanwhile, Hazel found she had a talent for garden design, and to her delight won the award for best courtyard garden at last year's Chelsea Flower Show.

This year, she is exhibiting at Hampton Court with what she calls "an idealised English vineyard garden". She designed it herself, and working on it with her are professional gardener Geraldine Chubb, nurseryman Colin Walton-Smith, and glass sculptor Gill Hobson. Sky TV is sponsoring the garden.

The RHS is offering Comet readers the chance to win free entry to this most magnificent of shows. All you need to do is answer the two questions on the entry form on the facing page. The first correct entry drawn will win a superb day out with two tickets, worth £54, for RHS members privilege day on July 6; a three-course gourmet lunch for two at the Roux Restaurant (usually £39 per head), plus a jug of Pimm's; one RHS gift membership (to use yourself or give to a friend) and a £20 gift voucher to spend at the RHS shop at the show.

The next two correct entries drawn will receive a pair of tickets, worth £54, for privilege day on July 6.

The next 10 correct entries drawn will each receive a pair of tickets, worth £44, for Saturday, July 10.

If you're not one of the lucky winners, you might find consolation with the RHS offer of two tickets for the price of one after 5pm on Thursday and Friday (July 8 and 9). This, ideal for people to visit after work, gives a saving of £14.50.

RHS members can enjoy the show at special rates on the two privilege days, Tuesday, July 6 and Wednesday, July 7. But they must book at least 48 hours in advance. Members' rates on the Tuesday will be £27 all day, or £17.50 after 3pm. On the Wednesday they will be £22 and £25.50 respectively.

Tickets for the public days will be £22 all day, or £14.50 after 3pm. Children aged between five and 15 will be charged £5, with free entry for those under five. The show will close at 7.30pm on July 8 to 10, and at 5.30 on July 11, when there will be a sale of display plants at 4.30pm. For RHS member booking, phone 0870 906 3790. For non-member bookings phone 0870 906 3791 or pay at the gate.