Born to be wild: William Robinson's legacy is still blooming at his former home

"A well-meaning, self-deluded fraud," laughs biographer Richard Bisgrove, making my gossipy ears prick up. "There are intriguing mysteries about where William Robinson got his money. He was talking about global warming long before anyone else, and battling with politicians about access to green space – and he was going on about grasses long before Piet Oudolf."

I'm spending an extended afternoon wandering around the gardens at Gravetye Manor in Sussex with Bisgrove, discussing his new book about the Victorian gardener. Robinson settled in Sussex after making his fortune running gardening magazines. He house-hunted in the countryside around London for years – roping in his more renowned colleague Gertrude Jekyll to help find his dream home – before falling in love with Gravetye Manor (these days, a posh country house hotel).

Robinson's significance for English gardening can hardly be overstated. Yet he's hardly a household name, especially compared to his pal Jekyll. Influenced by another friend, John Ruskin, Robinson's claim to fame was the invention of "the wild garden". To go wild in Victorian England was a big step – the accepted gardening style was, typically, an imperial spread of tender South American annuals across acres of lawn. But Robinson argued, loudly, that we should all be growing plants hardy in the British climate. His pet hate was gardeners spending hours digging up something they'd created only six months before. "Dig out your beds to five foot before planting, fill them with manure," Bisgrove explains, expounding Robinson's philosophy, "and then you'll never need to do it again." My heart sinks at the idea of having to dig a coffin-size hole before planting roses in future, but Robinson convinced many of his contemporaries.

At Gravetye this autumn, though, the radical arguments and experiments of the 1880s seem a long distance away. Cardoons hang – fading heads damp with rainfall – amid soft plantings of spiky blue perovskia and vivid golden crocosmia. And across the valley, hundreds of acres of native woodland also pay testament to Robinson's philosophy. If you can't make it here for the totally delicious afternoon tea, get a copy of Bisgrove's wonderful book, a full-colour romp in the company of a distinguished expert. Just make sure to read it with a scone.

'William Robinson: The Wild Gardener' is published by Frances Lincoln at £30. Gravetye's gardens are free if staying or dining, 01342 810 567 , www.gravetyemanor.co.uk

Victorian values: Robinsonian planting

'Rosa moyesii'

The rose is "Queen of Flowers", according to Robinson. The "most startlingly beautiful wild rose" for him was this geranium-red, free-growing beauty. £12.25 for a bare-rooted plant, www.peterbealesroses.co.uk

'Yucca gloriosa'

Robinson happily plantedpalms and exotics, as long as they could make it through the British winter. He thought this was "one of the noblest plants in our gardens". £12.50, from www.burncoose.co.uk,

'Clematis macropetala'

"Ernest Markham" is a summer-long flowerer, a climber that will sprawl to3m high. The original Ernest Markham was Robinson's head gardener at Gravetye. £7.99 for a two-litre pot, www.crocus.co.uk