Garden tourism is flourishing. The National Gardens Scheme (ngs.org. uk), where private gardens throughout England and Wales open for a day or two for charity, is expecting a record 750,000 visitors this year. In June, for example, you can visit the 10 acres of formal gardens at Lilburn Tower in Northumberland, or the steep riverside grounds of Waye Cottage in Cornwall. According to Stephanie Fudge, the organisation's business development manager, "People are drawn to great gardens. They want to see what's behind the garden wall, and take the lessons home." Whether we're looking for relaxation or inspiration, it seems that a day out to enjoy flowers and greenery has never been more popular.
The world's leading horticultural exposition take place once a decade in the Netherlands – and this is the year. Two million people are expected to visit Floriade (00 31 77 399 8130; floriade.com), which opens this week (5 April) and runs to 7 October. Its location is a specially designed site in Venlo, an old Hanseatic trading town that is now a centre for market gardening, located on the river Maas in eastern Holland.
The site was part forest, part agricultural land. The design for the exhibition incorporates elements of the local landscape, including several ancient burial sites. A new cable car, more than half a mile long, whisks visitors across the park. Admission costs €25. The Royal Horticultural Society (rhs.org.uk), which plans to launch a range of garden holidays for 2013, will soon announce a selection of tours based around Floriade, with departures from May.
Some 67,000 bulbs have been planted for Floriade, but it doesn't stop there. The bulbfields at Keukenhof (00 31 252 465 555; keukenhof.nl), a short bus ride from Amsterdam's Schiphol airport, can boast seven million, more than half of which are tulips in 100 different varieties.
The train journey from Venlo to Amsterdam takes just over two hours, making it easily possible for spring visitors to combine the two destinations; Keukenhof closes for the season on 20 May, and this year for the first time the gardens around Keukenhof Castle are being opened to the public. Leger Holidays (0844 504 6251; leger.co.uk) offers a three-night trip in April, visiting Keukenhof and Floriade for £199 per person, which includes escorted coach travel, B&B accommodation and entrance fees. In September, River Cruise Line (0844 544 6437; rivercruiseline.co.uk) will combine Floriade with the Rhine in a four-day cruise. Prices start from £469 per person including full board and cross-Channel ferry to join the cruise ship.
The green shoots of garden festivals are springing up all over the world. In France, the festival at Chaumont-sur-Loire (00 33 2 54 20 99 22; domaine-chaumont.fr), runs from 25 April until 21 October. Then, at the Domaine de Courson, also in the Loire Valley, the biannual garden festival, Journées des Plantes – 18-20 May and 19-21 October this year – is an opportunity to catch up on the latest in plant varieties and design style on the other side of the Channel. Courson is easy to reach from central Paris on RER line C2: during the garden festival, a shuttle service runs to the grounds from Massy-Palaiseau station.
Visitors to the biennial event in Singapore (00 65 25969; www.singaporegardenfestival.com) from 7-15 July will be able to enjoy a breathtaking collection of South-east Asian orchids; likely to be equally exotic is Floria 2012 (www.ppj.gov.my), which takes place in Putrajaya, a garden city slightly south of Kuala Lumpur, from 30 June to 8 July.
In the autumn (dates still to be confirmed), the third Gardening World Cup will be held in Japan. Founded by Kazuyuki Ishihara, the Japanese equivalent of Alan Titchmarsh, it brings international gardeners together, united by the theme of gardening for world peace.
The venue is Huis Ten Bosch (english.huistenbosch.co.jp), a purpose-built 17th-century Dutch town, 90 minutes by train or bus from Nagasaki. Complete with canals and a replica of the Dutch royal palace, it calls itself "a European resort of flowers".
The Gardening World Cup is modelled on our own Chelsea Flower Show, an ancient institution which transferred to its present location in the grounds of the Royal Hospital in Chelsea 99 years ago. Tickets for this year's show (22-26 May) are now in short supply, but for the first time it will have an independently run fringe festival (chelseafringe.com), and from 19 May until 10 June visitors to London can expect to find pop-up gardens and plant-themed installations on roadsides, in parks and in historic buildings all over the city.
Garden visits don't always have to be planned around an event. This autumn it is expected that the final part of the Australian Garden, at the Royal Botanic Gardens in Cranbourne, Victoria (00 61 3 5990 2200; rbg.vic.gov.au) will open, completing an important horticultural project and visitor attraction. It will reflect the country's landscape, from the arid Outback to the coast, with water, or the lack of it, as the central theme of the different parts of the garden.
Among the most ancient, and distinctive, gardens in the world are found in China, in Suzhou, a picturesque town whose canals earn it the nickname of "Chinese Venice". Spaces such as the "Humble Administrator's Garden" are a soothing mix of water, bridges and rocks, designed around a traditional house or temple.
A short distance from Shanghai, Suzhou is often included on the itinerary of organised tours of China, such as the 14-day "China Highlights" trip on offer from China Holidays (020-7487 2999; www.chinaholidays.co.uk) from £1,945.
Alternatively, for the ultimate historical overview, try the 14- or 17-day "Footsteps of the Planthunters" tour offered by Journeys of Distinction (0161 491 7616; jod.uk.com) whose itinerary includes a visit to the home of renowned botanist Joseph Rock in Lijang, in Yunnan province. There are departures in September this year and May 2013, and the price of £3,795 includes flights and accommodation with breakfast.
While the chateaux of the Loire Valley form a well-established tourist trail, many owners are looking for new ways to attract visitors, often by focusing on the gardens. As a result, several castles now open their grounds at night during July and August; these include the Renaissance gardens of Chenonceau (00 33 8 20 20 90 90; chenonceau.com) – the chateau which straddles the river Cher – and Villandry (00 33 2 47 50 02 09; chateauvillandry.com), whose formal beds are lit by candlelight. The Chateau de la Bourdaisière at Montlouis-sur-Loire (00 33 2 47 45 16 31; labourdaisiere. com) specialises in tomatoes, and has a collection built up over 20 years by its owner, the "gardening prince" Louis Albert de Broglie. Accommodation is in the separate Pavillon Choiseul, or within the castle itself. Doubles from €197, including breakfast.
Patricia Laigneau's family bought and renovated one of the oldest chateaux in the region, Le Rivau (00 33 2 47 95 77 47; chateaudurivau.com). They kept the moat and drawbridge and surrounded the building with a series of fairy-tale gardens based on well-known stories that include several hundred varieties of roses and irises.
One spectacular day out is at the Overhanging Gardens of the Chateau Marqueyssac in Périgord (00 33 5 53 31 36 36; marqueyssac.com), whose terraces are resplendent with thousands of boxwood trees in all shapes and sizes.
South Africa has eight national botanical gardens, the most impressive of which is Kirstenbosch (00 27 21 799 8783; sanbi.org. za) (pictured). Gardener and television presenter Monty Don, who recently returned from a horticultural trip to South Africa, rates this as one of the great gardens of the world, not just for its dramatic setting beneath Cape Town's Table Mountain, but for its extensive collection of native plants. "It was designed to preserve the flora of the country, and as such it's a part of South Africa's cultural identity," he says.
Part of the landscape within the garden is known as fynbos, one of the most diverse and unusual environments on the planet. The name refers to the shrubby, fine-leaved vegetation which includes carpets of colourful heathers, proteas, gladioli and other bulbs.
A short distance from Cape Town, in the wine country near Franschhoek, there's a very different type of garden. The eight acres at Babylonstoren (00 2721 863 3852; babylonstoren.com), one of the oldest Cape Dutch farms, contains 300 varieties of edible plants. The main house, outbuildings and workers' cottages have been stylishly rebuilt to provide accommodation, and rooms are available from R4,270 (£350), including breakfast.
A number of operators offer specialist garden holidays, often led by experts. Helena Attlee, a horticultural historian and specialist in Italian gardens, accompanies several of the trips organised by Boxwood Tours (01341 241717; boxwoodtours. co.uk). Other options in Italy are offered by Kirker Holidays (020-7593 1899; kirkerholidays.com); a six-night trip which departs on 6 June for the gardens around the Italian lakes of Como and Maggiore costs £1,825 per person, including flights, hotels, some meals and an expert guide.
Among the other companies with garden visits on their itineraries is Brightwater Holidays (01334 657155; brightwaterholidays.com). There's a diverse range of destinations from the Prince of Wales's garden at Highgrove to the Waterfall Gardens of La Paz, Costa Rica.
The Caribbean climate produces exotic flora, and in June there's a chance for visitors to Barbados to explore its horticultural attractions. Guests at the luxury Cobblers Cove in St Peter (001 246 422 2291; cobblerscove.com) can book a "Garden Tour" devised by the general manager Randall Wilkie and his colleagues. "There's enough sun, sea and sand here," he says. "We wanted to be different and show off some of our fantastic gardens." There will be visits to Andromeda Botanic Gardens, and to Hunte's Gardens, planted in a massive gully, as well as to at least one private garden.
The 10-day tour runs throughout June and costs from £1,540 per person, including B&B, garden visits and lectures. Flights extra.
Other people's plots
There are few things more satisfying to a gardener than poking around in someone else's borders – which no doubt accounts for the popularity of the National Gardens Scheme (ngs.org.uk). This year, it is celebrating its 85th anniversary, and 120 of the gardens which first opened to the public in 1927 will open again. Full details in the NGS Yellow Book, or at www.ngs.org.uk.
Garden writer Janine Wookey also runs day tours on behalf of the NGS, beginning with a day among the bluebells in Kent and Sussex on 25 April. Independent journalist Victoria Summerley's garden is also featured in one of Janine's tours, on 7 August. For details, go to www.gardentoursetc.co.uk.
The 38 small gardens that make up Barnsdale Gardens in Exton, outside Oakham (01572 813200; barnsdale gardens.co.uk) were created by the late Geoff Hamilton for Gardeners' World. Now run by his son Nick, Barnsdale also runs short courses in subjects ranging from composting to vegetable growing; prices from £18.
While Geoff Hamilton designed his garden as a TV location, other gardens were designed by artists. Claude Monet's Giverny, the subject of many of his paintings, is the foremost example (pictured). It consists of a flower garden in front of the house, and a Japanese water garden, which he added later.
Go by train from Paris St-Lazare to Vernon, and take the connecting bus (fondation-monet.fr/uk).
Jacques Majorelle also combined painting with an interest in horticulture, but his garden in Marrakech proved longer lasting than his pictures. It is notable for the tranquillity which its fountains and lush foliage provide in a busy, dusty city, and for the vivid shade of blue used to paint the buildings and large planters that feature. The Majorelle Garden (00 212 524 313047; jardinmajorelle.com) was later acquired by Yves Saint-Laurent, whose ashes are scattered there.
Restoration has brought several of our own historic gardens back to life. These include Wrest Park (0870 333 1181; english-heritage.org.uk), at Silsoe in Bedfordshire (pictured), whose garden design originated in the early 18th century. The Italian and rose gardens are now open to the public, and work is continuing to restore the other formal gardens and an extensive woodland area.
At Trentham Estate (01782 646646; trentham .co.uk) just outside Stoke-on-Trent, work has begun to prepare the North Park for the recreation of the 18th-century woodland. But the gardens at Trentham are now fully restored and their attractions include the brightly coloured Floral Labyrinth, the Rivers of Grass, and an Italian garden with more than 400 plant varieties.
Cornwall's two main horticultural attractions, the Eden Project (01726 811911; edenproject.com) and the Lost Gardens of Heligan (01726 845100; heligan.com), will be running seasonal events throughout the year.
In June, the gardens run by the Royal Horticultural Society (rhs.org.uk), will offer activities for the Diamond Jubilee.