Alan Titchmarsh to ZZZZZ: The Complete Guide to Chelsea

On the eve of the greatest flower show on earth, Victoria Summerley takes you on a walk up the garden path with her A-to-Z guide

A is for Alan Titchmarsh, who despite making a new gardening series for ITV, will be the anchor for the BBC's coverage of Chelsea. Sick of the sight of him? Tune in at lunchtime, when the garden designer Andy Sturgeon will be presenting (BBC1, 12.30-1pm).

B is for Bulldog, the only manufacturer of garden tools which is 100 per cent British. Based in Wigan, at Clarington Forge, the company is building its first show garden at Chelsea this year, the theme of which is, appropriately, a blacksmith's garden. It's set in the 1940s and the idea is that it belongs to a self-sufficient blacksmith making his own tools and growing his own vegetables and flowers, in an era that saw hundreds of similar small enterprises all over the UK.

C is for celebs, who range from rock stars to Royal Shakespeareans to Rolf Harris. Some will be championing charities, some will be giving their name to a new plant variety and some will just be there to have their pictures taken – sorry, because they like gardening. Keen gardeners include Sienna Miller, Ringo Starr, Joanna Lumley, Imelda Staunton and Raymond Blanc.

D is for designers. Some, like Diarmuid Gavin, Cleve West and Luciano Giubbilei, are established names, while others are only just beginning to make their mark. Look out for the RNIB garden, designed by Paul Hervey-Brookes, who won the Chris Beardshaw Mentoring Scholarship at Malvern in 2009. Another Chris Beardshaw scholar, the 2010 winner Maria Luisa Medina, is working on the Bradstone Fusion Garden.

E is for Endeavour, the ship in which the naturalist Sir Joseph Banks, a founding member of the Royal Horticultural Society, sailed to Australia with Captain James Cook on a voyage of scientific exploration. It's commemorated in the Trailfinders Australian Garden, by Fleming's Nurseries, which includes many of Banks's botanical discoveries.

F is for flying garden, which will feature in the Failte Ireland garden designed by Diarmuid Gavin. What looks like a UFO will be suspended from a crane above a series of pools. At Chelsea 2004, Diarmuid famously had a spat with designer Bunny Guinness, who is returning to Chelsea this year after a gap of eight years. F is also for fisticuffs. Let's hope there aren't any.

G is for grasses, a must-have in any self-respecting garden. There's a grass for every situation – many do well in pots and containers too. Neil Lucas of Knoll Gardens is the man to ask – his book, Designing With Grasses, published by Timber Press, tells you everything you need to know. You'll find Knoll Gardens' stand in the Great Pavilion.

H is for Herbs, and Hooksgreen Herbs, which is exhibiting at Chelsea for the first time. Its speciality is culinary herbs that look as good as they taste. Varieties will include ginger rosemary and blackcurrant sage. H is also for the Hampton Court show, where you'll want to go if you couldn't get tickets for Chelsea. Details at www.rhs.org.uk

I is for the Ishihara Kazuyuki Design Laboratory, which every year produces one of the most charming and intricate gardens at Chelsea. They are meticulously planted with extraordinary attention to detail. This year's design is called A Beautiful Paradise, and it is intended "to evoke nostalgic thoughts and to soothe the soul".

J is for Japanese tree peonies, featured in a special display by Kelways, which is celebrating 160 years in business. Kelways began as a gladiolus specialist but changed tack thanks to the opening up of China and later Japan. By 1900, Kelways had introduced more than 1,000 peony cultivars. J is also for James Wong, who is creating a show garden inspired by the rainforests of Malaysia.

K is for Korean lavatory, specifically the one in the Hae-Woo-So (Emptying One's Mind: Traditional Korean Toilet) garden. This design was created by artist Jihae Hwang, who wanted to present a spiritual oasis where you can free yourself of anxious thoughts, re-attune your body and attain peace. And go to the loo, presumably.

L is for luggage – you'd be amazed at how many Chelsea visitors turn up with suitcases in tow. Plant Heritage operates the cloakroom, which is on Ranelagh Gardens near the London Gate (the Royal Hospital entrance). You can dump coats, cases, picnic baskets and purchases for the price of a small donation.

M is for Matthew Wilson, who has designed the planting scheme for the RHS Experience, which offers planting ideas and ways of solving problems such as shade. M is also for Monaco, whose first show garden is by award-winning British designer Sarah Eberle. It will demonstrate that if you live in a tax haven, money really does grow on trees. Only joking – it's about how landscape and architecture interact.

N is for nostalgia (see also B and V), which is always a popular theme at Chelsea. Contemporary designers such as Cleve West and Luciano Giubbilei may win gold medals and best in shows, but if you want to win the People's Choice award, then conjure up a bit of cottage-garden action.

O is for orchids, and there are several displays to choose from. British specialists include McBean's and the Orchid Society of Great Britain, while the orchid growers of Taiwan and Thailand's Nong Nooch Tropical Garden will also be exhibiting.

P is for photovoltaic technology, which is what the Skyshades garden uses to supply power for its garden office, or studio. Unlike conventional solar panels, which are glass, the Skyshades panels are made from solar film bonded on to tensile panels, so they are much lighter. It may sound very high-tech, but the emphasis in this garden is on biodiversity, and the planting is designed to support 200 species of wildlife.

Q is for questions. Every gardener has them, whether you want to know why your wisteria never flowers, or how to keep squirrels from eating your tulip bulbs. The RHS Advisory Service will be at the show to answer queries – you'll find them at the RHS Experience display.

R is for roses, of course, which provide some of the lushest displays in the Great Pavilion. The organic types among you might be cheered to know that roses don't necessarily mean endless spraying and chemical intervention. Michael Marriott of David Austin, who designs many rose gardens for its clients, has run his own garden on organic principles for 22 years – he uses companion plants to attract beneficial insects.

S is for Skyfarming, which is why you will see a nine-metre tower covered with edible plants at Chelsea this year. The principle is that you grow crops hydroponically in vertical structures, rather than take up room on the ground. Does it work? The jury's still out, but you can find out more at the B&Q garden, whose tower it is.

T is for tea, as in Jekka McVicar's new range of organic loose-leaf teas, made from herbs and flowers and blended on Jekka's farm in south Gloucestershire. T is also for temples, which are back in a big way, according to Chilstone, the architectural stone specialist. Its show garden, designed by Heather Appleton, features a neo-classical stone temple on a deep-pile turquoise outdoor carpet. Sales of temples and follies are up 30 per cent year on year, apparently. Who knew?

U is for Unsung Heroes – people like Mary Payne and Jon Wheatley, who this year are working on the Bulldog Forge garden. They may not be household names, they may not get into arguments with Diarmuid Gavin, but they are responsible for some of the best displays you will have seen at the RHS shows.

V is for the valleys, boyo, as in Welsh valleys. Students from Ysgol Bryn Castell & Heronsbridge special needs schools, under the guidance of the designer Anthea Guthrie, have come up with a nostalgic garden set in the heart of the Welsh Valleys in 1947. Traditional fruit and vegetables take up most of the space but the children get to grow a few annuals among the crops.

W is for wedding. Yes, look away now, because there will be plenty of Wills 'n' Kate tributes. Guaranteed to be one of the most popular is the new David Austin English rose William and Catherine, a Musk Hybrid with creamy-white flowers. Heucheraholics has based its display on the theme of the royal honeymoon getaway, complete with a bootful of Heuchera Beaujolais, H. Pinot Gris and H. Pinot Noir.

X is for Xeriscaping, which involves the use of drought-tolerant plants to cut water use. Ironically, in the driest spring the south and east of England has known for years, many of the show gardens include lots of water. So for advice on coping with dry conditions, head for the Great Pavilion and seek out grasses specialist Knoll Gardens, Craig House Cacti and Todd's Botanics.

Y is for Yorkshire, in particular the artists of Yorkshire, who include Henry Moore, Barbara Hepworth, David Hockney, Andy Goldsworthy and JMW Turner. They are the inspiration behind the Welcome to Yorkshire garden, which will include Barbara Hepworth's sculpture Ascending Form (1958).

Z is for a quick zizz, which is what everyone exhibiting at Chelsea will need after months of sleepless nights worrying about the effect of cold and drought on their plants in the worst winter and driest spring for decades. It will be a very quick zizz, though, before the planning for next year's show begins...