Royal Botanic Gardens, Kew says its "new business model" is working at its Wakehurst Place country garden, where parking fees introduced in 2014 saw a big drop off in visitor numbers.
Wakehurst Place, which is a National Trust property leased to Kew, attracted 350,000 visitors in 2013 but that fell to 180,000 in the 2014-15 financial year after the car park fee came in during April 2014.
Kew said the £10 daily parking fee for National Trust members, who made up 80 per cent of Wakehurst visitors, came in because the site had a £1.4m deficit and running costs of £2.2m.
A Kew representative said: "We ended 2014-15 with a healthy 180,000 visitors and a year on from introducing a new business model our visitor figures are steadily growing. The spring and Easter periods were highly successful and our recent summer event, the Wild Wood Weekend, saw a 160 per cent uplift in visitors against the same bank holiday weekend last year.
"We have also seen direct income from visitors grow by almost 50 per cent and annual membership has grown by 450 per cent. These results are hugely positive and indicate that the decision to introduce the changes at Wakehurst will pay off in the longer term and allow us to invest in Wakehurst."
Director Andy Jackson, who was awarded an MBE in the Queen's birthday honours list, retired early last month after 31 years at Kew, including 25 years at Wakehurst Place, where he was in charge for 12 years.
Kew director Richard Deverell pointed out that Jackson put Wakehurst on a "firm financial footing for the future by laying the foundations of an emerging new business plan that has already seen direct income at Wakehurst shoot up by 47 per cent and membership numbers climb from 2,000 to more than 9,000 in a year".
Catharine Pusey will be the acting director at Wakehurst Place until a new director is taken on to start work in September.
Protestor's claims Income down and season ticket sales low
Wakehurst Place parking charge protestor Mike Joyce, who has submitted several freedom of information requests about Kew, pointed out that as well as visitor numbers dropping at the attraction, catering and retail income have almost halved and season ticket sales of 7,145 - at £25 - to 28 February 2015 are fewer than the 30,000 that Kew had targeted.
Wakehurst Place's visitor entry revenue from the introduction of car parking charges until March this year saw it take in £645,606, up from £326,802 the previous year. Retail revenue fell from £770,559 to £407,970.
Joyce said there were 43 "terrible" or "poor" TripAdvisor reviews in 2015 out of 78, mainly complaining about parking fees. TripAdvisor has now removed the negative reviews and said: "They were talking about a parking charge, but they weren't actually talking about them going to the attraction.'
Kew said: "Over the course of the past year a handful of reviews have been flagged by RBG, Kew's digital team. Only TripAdvisor has the authority to remove reviews."