The show, which originally ran from 1888-1911, commemorated the 400th anniversary of the granting of the Royal Charter to the Inns of Court at the Inner and Middle Temple in London.
The RHS is believed to be extremely keen for Britain's top lawyers, who have their headquarters at the Inner Temple, to agree for the show to return in 2009 - if it can get sponsorship. This year, law firm Freshfields Bruckhaus Deringer backed the show.
Original exhibitor Waterers was there with its rhododendrons, while other highlights included Raymond Evison showing century-old clematis cultivars and Somerset-based Pennard Plants selling its heritage vegetable seeds.
RHS shows director Bob Sweet said: "We were here to help the Inner Temple celebrate 400 years and the historic link between the site and the RHS Chelsea Flower Show. Nearly every exhibitor is connected to Chelsea or what happened here 100 years ago.
"This is a really interesting opportunity for us. We've had a terrific response to ticket sales. We pre-sold 12,000, and 15,000 in total."
He added: "We're here as a one-off but the RHS would be more than willing to come back.
"The number of big shows is almost at a maximum capacity in this country now. We've enjoyed huge success with small-scale shows we've put on. Wisley in August attracted 20,000 visitors, and Cardiff in April 15,000. They're more cost-effective and have an intimate, more informal feel. It's a nice model."
HW writer Peter Seabrook, who designed a balcony garden at the show, has long wanted the RHS to put more energy into its London Horticulture Hall shows, one of which Inner Temple replaces. He said: "Inner Temple attracted one hell of a crowd. The show illustrates what can happen when the RHS holds a show in London and publicises it. RHS fortnightly shows can be just as successful if they encompass the energy of this show."
John Woods managing director John Lord: "It's not enough to have a good-quality plant these days - that's a given - you have to have something else to offer, either brand or heritage. We have brought stock to promote the garden-centre stockists of (century-old rhododendron brand) Waterers. The brand has grown 10 per cent a year for the past three years. I don't think that plant-disease scares are affecting us at all."
Clematis owner Raymond Evison: "It's a lovely little show. Our collection was of old cultivars (including Marcel Moser 1896, pictured with Evison). I think small shows are more fun and intimate and have a lot of attraction. But because of the small area you can't get a vast amount of people in."
Royal Hospital Chelsea head gardener Ron Willmore (pictured with Chelsea pensioners Fred Butterfield, left, and Mike Dows): "We were asked by the RHS to show as a link between Inner Temple and Royal Hospital Chelsea. We showed Coleus, which we have used in the hospital's wards. Coleus is out of vogue now but is very easy to propagate and quick-growing. Plans are afoot to extend the commercial side - a place to sell plants attached to the museum to raise money for its ongoing appeal."
Inner Temple head gardener Andrea Brunsendorf: "In the past year we have introduced new herbaceous borders. They were rather municipal. Now we have one of the longest herbaceous borders open to the public at 70m long.
"We have found unusual dahlias, Helianthus and Rudbeckia from the plant centres at Beth Chatto's garden and Great Dixter."
Pennard Plants co-owner Chris Smith: "Our heritage seed varieties have taken off in the past five years. Anyone can grow them anywhere, even on a balcony or windowbox. They aren't F1s and aren't available in supermarkets, so they are quite unusual."
Inner Temple gardens will be open as part of London's open garden squares weekend (www.london gardenstrust.org) on 14 June 2009 and for the National Garden Scheme on 4 October 2009.