With careful planning and a little trickery the smallest garden can have the biggest impact. These are the encouraging words from garden designer Andrew Wilson, director of the London College of Garden Design, Kew Gardens, who will be talking on Saturday at the RHS London Plant and Design Show.
"Don't be confined by your starting point," says Wilson. "Larger works better in a small space, whether pots, plants, structures or sculptures. If an ornament looks great in your living room, it won't work in the garden: you need to go bigger. Making strong decisions about fewer elements will deliver the impact you want."
Lighter-coloured paving materials such as limestones and sandstones will reflect light into the space, and are especially useful in shade. "Dark materials such as slate or basalt will absorb light, but will be more atmospheric."
Boundaries, especially if they are different on all sides, make the garden look bitty. "The problem with town gardens is that you're not in ownership of all your boundaries, so you might have one wall here, one fence there. By painting the wall and staining the fence a similar colour you can unify your backdrop," suggests Wilson. "Be wary of hot, bright colours that will make the space look smaller; black or dark green will reduce the impact of the boundaries and will also make a great foil for your planting scheme."
Every small garden, points out Wilson, has one feature that is on a huge scale. "It is open to the sky, unlike a room indoors, so really use that vertical space. An arch or even a pergola will take a flat plane to another level, as well as give you the opportunity to grow climbers and vines. Most off-the-peg pergolas and arches are too thin, too small and some collapse after a short while under the weight of the plants. It's worth investing in strong, sturdy structures. The height should be at least 2.2 metres, because you need to allow for the extra space that plants will take, and you need to make the width wider than the path, so the bases can be inset into the beds and will be concealed by the planting."
Lighting the garden will give you a view to look out on in winter, plus give you more hours to spend outside in summer. "There are two schools of thought," says Wilson. "You can keep lighting subtle and concealed, washing walls and key shrubs or trees with soft light. More recently, though, there is a move towards outdoor lights that themselves have impact, like the Philippe Starck anglepoise outside light, so you get a design hit during the day, too. Another plus is that they're portable, so you can drop some light over your patio dining table when it suits you, or another time, focus it on a statement plant or piece of sculpture."
Give as large an area as you can to planting. "People tend to push everything back to the boundaries in a small space, but narrow beds can only offer thin, weedy displays. Beds of 1.2- to 1.5-metre depth will enable you to layer plants so you can have different heights as well as seasonal changes. You'll get a better result with 10 or 15 plants of one species than lots of different ones, so aim for fewer species, but more of each. Massing plants together gives you a colour intensity. Create visual drama with tall plants such as Veronicastrum, which has tall, elegant flower spires, and tall grasses such as Miscanthus Silberfeder, then add perennials at a lower level, such as geraniums and salvias. Choose plants that do more."
A favourite trick of Wilson's is to put up a wall, either to create an intimate space, to screen off a shed, or simply to highlight plants. "Render the wall the same colour as the house to produce a cohesive effect," he says. "A pale wall makes a great backdrop for strong, colourful planting and, depending on where the sun falls, provides lovely shadow play from the plants' silhouettes. It will also reflect light during the day, bringing more light into the space."
Andrew Wilson can be contacted at Wilson McWilliam Studio (wmstudio.co.uk).