Festival International des Jardins, Chaumont-sur-Loire (until 20 October);
The International Westonbirt Festival of Gardens, Gloucestershire (until 8 September);
Chelsea Flower Show (20-24 May)
Chaumont, now in its 11th year, aims for the avant-garde, though within constraints.
Competing designers have 250m 2standard plots almost surrounded by 2m-high beech hedges, a restricted construction budget, and a show span of five months.
Westonbirt is new this year, in many ways following the Chaumont model, though its 150m 2plots are unbounded, which presents both an opportunity and a problem for designers. Westonbirt does have the advantage of being sited at the centre of the National Arboretum, near Tetbury, which already attracts 300,000 visitors per year.
Chelsea is familiar.
In many ways, the more adventurous garden designs from these three shows have more in common with each other than with others at their particular show. But there are some show-specific threads, especially at Chaumont, which each year has a design theme. This year's is l'érotisme au jardin, which, unusually, many designers have found difficult to make good use of.
A few go for the obvious and banal - some with a better horticultural eye for cucumbers and melons than Sarah Lucas, but less sculptural imagination.
Others mainly address the theme in their design descriptions. But some designers have found inspiration, such as Luis Bisbe (and colleagues) from Spain, who took the idea of veils in their garden Flou (blurred).
Parallel lines of white translucent fleece (like net curtain), 2.5m high, spaced 2m apart, cross the plot and push out through the surrounding hedges. Walking in the garden through holes cut in the veils, you see plants through different numbers of veils and thus varying translucency. The tall plants complement this, chosen for their see-through open structure (for example, corkscrew willow), and the occasional flowers are white as well.
Les Pétales du Désir by Eric-Pierre Ménard (and others) is a giant flower sculpted in tubing wound with hemp rope, strong-smelling in the rain, with other vertical tubes standing for stamens. In exploring this garden you walk inside it and touch it, a contrast to most galleries. It gives an extraordinary sense of being part of the plant, and of being transported to another scale.
Several designers take their lead from the idea of a clandestine rendezvous, with secret inner gardens, tree houses and arbours.
Bertrand Houin and Christophe Ponceau's Et Vice et Versa includes bottle-shaped willow arbours. And in case you are reluctant to try them, an overhead system of sprinklers comes on every few minutes to encourage you to take shelter.
Mirrors, misting and minimalism have been Chaumont themes for years. The show is tending to grow out of the routine use of the commoner 'architectural' plants. Planting tall at the front of borders, rather than the usual small-to-tall, front-to-back, can add an extra dimension. Past examples majored on the tall, open-structured verbena bonariensis. That plant has largely gone this year, replaced by several others such as the single-stem, lance-like, horsetail rush.
Over the years, Chaumont has been a showcase for emerging uses of materials, such as recycled shredded coloured plastic and glass fragments used as mulch. Mulches can be critical to long-life gardens when plants start small, but at Chaumont they have often remained foreground, not just background, all season. This year, the stylistic litmus has led several designers to pick up on dyed wood chip mulch in black, pink and other bright colours. (L'Atelier's Westonbirt garden using charcoal mulch may find the colour longer-lasting in sunlight. ) Surprisingly, Chaumont has yet to explore reinterpretations of classical planting, despite the proximity of Villandry and other formal chateaux gardens.
At Chelsea this year, especially in the major gardens, the emerging themes were cottage garden planting and that 'natural' look - planting for escape. And as artificially instant and impossibly lush as usual. Those that risked embracing the future were in the harder-to-find smaller gardens (are Chelsea's show-guide maps the worst ever? ).
'Clearwater' by Mike Walker and Sarah Wigglesworth created a delightful sequence of reed beds for processing grey water, to make a desirable front garden. (Is that a straw bale in the background? ) In an even smaller space, Roger Bradley and James Carey's 'Love Learn Live' included several red plexiglass boxes that both structured the space sculpturally and acted as mini-greenhouses, creating microclimates and increasing plant variety.
One of Chelsea's main drawbacks is its brevity and the resulting crowds. Its gardens could not cope with being entered. A crowded Chelsea visit is reminiscent of a local fête, filing past those tables of children's garden-in-a-seed-tray exhibits. The experience is almost two-dimensional. The length of show removes this restriction at Chaumont and Westonbirt. Even so, Chaumont's identical, enclosed plots are also formulaic, a restriction for designers after 11 years. Apart from developing Chaumont's other attractions - the Valley of Mists, the Experimental Garden and the Trail of Wild Iron (steel sculptures on a woodland walk) - it is difficult to see where Chaumont goes next.
Simply throwing away the hedges is not the answer, as Westonbirt demonstrates.
There, plots are scattered around a too-large flat field, leaving many of the 19 gardens floating context-free. The more successful ones tend to be close enough to the existing perimeter planting of mature trees and bushes to relate to these, or to the occasional mature tree within the field.
Sally Court's 'As the Crow Flies' has a 'riverbed' of stones that could have sprung from the undergrowth behind, and she then weaves it among mounds she has created on this otherwise flat site. Ex-Chaumont designer L'Atelier's 'Serial Garden' also abuts the perimeter hedge, extending from it nine contiguous planted strips, framed pergolalike in tube and node scaffolding. Coloured translucent screens hang between the strips when the wind drops. Their planting is a variation on the potager, emphasising colour and shape, with nasturtiums among broken pot shards, ruby chard, charcoal mulch, fennel and climbing beans.
A few other designs have a chance to relate to the occasional trees within the site.
'Fjord' by Stephen Woodhams is a sculptural piece suggesting ice fields, which sits amid three pines with 'icicles' suspended overhead from cables between the trees. Another garden starting at a clump of trees and bushes, and exploiting Westonbirt's opportunity of not having a fixed plot shape, is Tony Heywood's 'The Happening'. Its long, zig-zag, meandering path is an abstract representation of nature's cycles, its planting integrated with metal sheet, glass panels, wire wool, slate and more.
Morgan Stainton Design's 'The Round Garden' simply makes its own space by looking inward, sited behind a 2.5m-high encircling wall. Inside there is a stunning display of flowering plants. That was June - what will it be like by the end of August? Architect Roderick James' 'Treedial', a variation on the sundial, makes its own space through sheer size. Earth is mounded into an enclosing wall planted with grasses. Inside the floor are glass chips, and in the centre an array of inclined timber spars with a central vertical spar rising to 24m, all connected by steel cables.
This is Westonbirt's first year. In individual designs, it is a promising start.
Sponsorship is being undertaken by the site owner, the Forestry Commission. There is confidence already that this will become an annual show. Though next time, with hoped-for commercial sponsors, there should be more than 19 gardens.
But even if the field is filled (like Chelsea), more structure is needed. Whether siting more gardens near the existing perimeter planting, introducing planting, earth mounding or water, Westonbirt needs to create more context for the designers to work with. You can cram stalls at a fête next to each other, but gardens reach out beyond their borders.
Chaumont is a short walk from Onzain station on the Paris-Amboise line