While many of the events and activities lined up to mark the occasion focused on the gardens' historical emphasis, there has also been a strong focus on how Kew can be relevant in the 21st century and beyond.
Challenges of funding — Kew is part funded by public money — and changes in climate are likely to be dual themes that will affect what the organisation does and how it does it. It could be a daunting task, but new Kew chairman Marcus Agius relishes the challenge.
As group chairman of Barclays, Agius is well accustomed to weathering financial storms and the coming years at Kew will see his business acumen tested. One of his main aims is to roll out Kew's Breathing Planet Programme, which aims to work globally on conservation, education and restoring habitats.
"We are going to turn the Breathing Planet Programme into reality and for that to happen we will need to raise an awful lot of money," admits Agius, although he will not reveal the extent of the sums required.
He will work closely with Kew director Stephen Hopper and newly appointed Kew Foundation development director Michael Murphy on the campaign. "Murphy is a seasoned fundraiser," explains Agius. "He has just completed a £100m campaign at the Royal Society so we'll be working on bringing it all together."
Although Agius is technically still also chairman of the Kew Foundation, an independent charity, he will be replaced in the role shortly. "It is important to keep things separate," he says.
With so many interests — Agius is also involved with the BBC and a non-executive director at Exbury Gardens, which is owned by his wife's family, the de Rothschilds — it is hard to imagine how the 63-year-old can fit everything in. But his motto has been "fun, business, money", and as a passionate gardener, Kew fits perfectly in that mantra. "In my pathetic little way I am a keen gardener," laughs Agius, somewhat modestly considering the extent of his garden at his home in Hampshire.
"I very much use it as a form of therapy — it is a good way of letting off steam. I can take things out on the shrubbery. As a teenager, I remember sitting at the table with my parents going through seed catalogues and thinking there must be more exciting things to do than this. But now, like all gardeners, I wish I had started about 20 years earlier."
In addition to the major work Kew will be doing worldwide on horticultural and environmental issues, closer to home appealing to children is a major mission. They will be Kew's future visitors and Agius hopes the gardens can help inspire more youngsters to realise the value of horticulture.
"There is a quasi-educational play area but I think children of an older age are curious and want to find out more," he suggests. "There is a lot more we can do to help people understand what is going on in the garden better than we do. But we have to get the balance right — some people just want to go and have a walk in the garden, while others have a greater horticultural interest."
The economic climate has benefited Kew, adds Agius, as people visit attractions in the UK rather than going on holiday. Draws such as the treetop walkway have also helped, he notes, although its broken lift has been a "running sore".
The organisation's reputation should mean it is not a major casualty in any public spending squeeze, Agius believes. "The good news is that Kew's financial needs are not large in the context of our sponsoring minister," he explains.
"We are not the biggest problem they have. Kew is well regarded by Defra and seen to be doing well and I am hopeful those factors will be taken into account when it makes its deliberations."
The green agenda and climate change could also benefit Kew long term. "The green agenda is increasingly in people's minds and we need to show them that Kew can play a vital part in the climate change issue, and that it is not just a nice park," he insists. "It is not going to be easy but we will put our shoulder to the wheel."
1972-2006 Investment banking, Lazard
2002-06 Chairman, British Aviation Authority
2006 Appointed as senior independent director, BBC
2006 Joins Barclays Board
2007 Appointed as chairman, Barclays Group
2009 Appointed as chairman, board of trustees, Royal Botanic Gardens, Kew