Sophie Walker was the youngest ever woman to design a garden for the Chelsea Flower Show. Her 'Cave Pavilion' of 2014 was a 21st-century interpretation of a plant hunters Wardian case. A modern Perspex structure was fronted with a white frame through which visitors could view a dense tangle of jungle including many plants not seen before in cultivation. For this garden and her 'Valley Garden' at Hampton Court, Sophie worked closely with plant hunters Sue and Bleddyn Wynn-Jones of Crûg Farm Plants. Her designs reflect her fascination with wilderness and our response to it. When it comes to planting Sophie seeks to replicate nature at its most untameable; her 'Valley Garden'  featured a concrete-edged slice of land, the viewer was gradually immersed, becoming surrounded by dark water and a tropical thicket of glossy foliage.

What are you currently working on?

I'm designing The Round Dell at Borde Hill Gardens, overlooking Haywards Heath. I've made a path that slices right through the space, it's very linear and directive - the straight line is the only thing nature can't do. In the Bahamas I've recently dug up and planted a garden that had been covered with tarmac; I've replanted it as a native forest that leads down to an ocean dune to the sea. I'd like to revert more tarmac! 

Describe your aesthetic - what or who would you say inspires your work?

I feel it's my role as a garden-maker to set up a system in which nature can function and 'take place'.  The jungle is the most engaging example of that and it was in the Amazon jungle that I resolved to study horticulture.  I hope my gardens can feel as 'all-over' and as intimate as jungle.  I'm looking for something only nature and time can do.

Do you have an all-time favourite plant? If so what is it and why?

I enjoy the challenge of working with plants that I've not come across before.  For my last garden at Chelsea Flower Show, I worked with 21st-century plant hunters Sue and Bleddyn Wynn-Jones. We only used plants that they had collected themselves from seed and had never been seen at Chelsea Flower Show before.  We included a number of new plant species and even a new genus.  We have only catalogued about a third of the plants on earth, this fact amazes and saddens me because so much of the uncharted habitat is under threat, and there is so much to learn from the plant kingdom, not least in medicine.  Around two thousand plant species are newly described each year… So there's plenty of material to work with!

What is your earliest garden memory?

I remember watching The Tempest beside the lake at Stourhead when I was five years old, and I've had dreams about it ever since.  We had a house in Dorset on the River Frome and my parents would take me to visit Thomas Hardy's garden and we'd drive around the local countryside visiting sites from Tess of the d'Urbevilles.  From an early age I had a sense of the relationship between landscape and the other arts like literature and painting.

Who taught you to garden?

When I was a child, my Mum and I would make the Easter Garden on her baking trays every year on Good Friday - I'd ram soil over a jam jar for Christ's tomb and cover it with red camellia flowers we cut from the garden.  I trained in horticulture at Capel Manor College which was the best education I've had, but really gardening is a matter of intuition - you self-teach to feel for a plant. 

Tell us about your own garden - what do you grow there? 

I'm planning my own garden at the moment - it's most people's nightmare space - a dark basement garden underneath a London pavement.  I have the great Italian grottos in mind, except I am making a London grotto, damp and dark, growing with fungi and ferns...  Then, punctured into the top floor of the building my roof garden is based on Cave Pavilion, my Chelsea Flower Show garden.  It is a real courtyard garden to be looked at from inside. 

Do you have a favourite garden?

The Japanese garden has had a huge influence on me.  It is so intellectually astute and playful at the same time - shifting in scale so that rocks are not simply rocks but mountains.  I've been so persuaded of its importance that I am currently writing a book on the abstract, conceptual nature of the Japanese garden which will be published by Phaidon in spring 2017. 

TOP TIP

Gardening relies on intuition, not knowledge.  To have a feeling for a plant is the most important thing, and that's a question of language, not knowledge.  We have to think outside of convention and cultivate the garden as a place of play, discovery and imagination in which we might invent something new for ourselves, and therefore for the world.