No funeral. No memorial service. No ‘Celebration of Life’. The decree was issued, and, as she could be quite a firecracker when crossed, her friends reluctantly obeyed. But for those of us who sorely missed Valerie Finnis’s telephone calls and hand scrawled letters, there was something flat and gloomy about not having a chance to share stories, to remember the gardener, photographer, creator of plants, agent provocateur, fairy godmother to young gardeners, maker of mischief and generous friend.

So it was with pleasure and relief that, six months after she died and just as the powdery blue Muscari Valerie Finnis poked up, an invitation arrived to celebrate the launch of the book she was working on for the last two years of her life. Best of all, the ‘launch’ was a lunch at her home and her garden at the Dower House of Boughton House in Northamptonshire, where she arrived as a bride, aged 46, with a dowry that consisted of a distinguished alpine collection and nearly 50,000 transparencies of flowers, gardens and gardeners.

She loved to tell the story of how she met her husband, Sir David Scott, a cousin of the 8th Duke of Buccleuch. She was working in her alpine nursery at Waterperry Horticultural School near Oxford, when she heard a voice exclaim: ‘She’s got Gillenia trifoliata.’ He was the first person who’d ever known the plant, and their marriage soon after was proof that, in the English gardening world, plant recognition is as seductive as moonlight.

If the marriage of the 46-year-old specialist in saxifrages to the 82-year-old retired diplomat sparked gossip, Valerie wouldn’t have minded. Gossip was a sign of passionate curiosity and she adored it, especially when joined with the little feuds that set her going like a fat, gold watch. In 1975, she received the RHS’s greatest accolade, the Victoria Medal of Honour. There are only 63 holders of this medal at any one time the number of years of Queen Victoria’s reign but medals didn’t mellow Valerie. In 1995, when the RHS decided to move its world-famous Lindley Library from Vincent Square to Wisley, she mobilised her troops like a natural born freedom fighter. Sir Simon Hornby, the society’s president, who strongly supported the move, never knew what hit him. The Lindley Library stayed put.

Perhaps Valerie’s greatest legacy is the Merlin Trust, which she set up in memory of her husband and his only son, Merlin, a gifted naturalist who was killed in the Second World War, aged 22. The trust gives travel grants to young gardeners.

Like many childless women, Valerie never lost her magical sense of childhood. The party’s host, Lord Dalkeith, described how invitations to his siblings to come for tea were written on scrolls of silver bark, placed in the corkscrew of her pug’s tail and dispatched. On a visit to Wyken, she hid a one-legged lead soldier in the yew hedge. After lunch, she told Sam, then six, an elaborate story that ended with him finding the soldier. Months later, I read Charlotte’s Web to Sam, a book about friendship on earth, adventure and miracle, life and death, and a clever spider who cannot stand hysterics. When I reached the end, he said: ‘I think that Charlotte is just like Valerie Finnis.’

A book of Valerie’s photographs and memories, written by Ursula Buchan, is published in May, coinciding with an exhibition at the Lindley Library. It’s as if a very clever spider has spun the notice: ‘Valerie Finnis. Lindley Library. Vincent Square.’