Nursery owner John Massey showed all 12 species of hepatica together with a range of inter-species hybrids including some of his own introductions.
This was the first time the plants have ever been seen as a single exhibit at Chelsea.
The Ashwood team have previously struck gold twice before at Chelsea – in 1996 with a lewisia exhibit and in 2005 for their hydrangeas.
Philip Baulk and Rupert Golby helped create the display.
Both Carol Klein and Rachel de Thame visited the stand, interviewing John for the BBC TV Chelsea Flower Show coverage, broadcast on Wednesday night’s programme, when Massey said this could be his last Chelsea display.
The semi-woodland landscape evoked the natural habitat of hepaticas using a soft billowing canopy of Larix kaempferi ‘Diana’, Japanese cherries and dwarf shrubby willows.
Massey said: "Being given the Diamond Jubilee Award for the best exhibit in the Great Pavilion just means so much to me. I wanted the display to tug at the emotions and I hope I’ve succeeded in doing just that."