Kate Gould and Ian Price won gold in the fresh category.
G-Lion, IBTC Lowestoft, Seedlip, Viking, World Horse Welfare and Walker's Wharf won gold in the artisan category.
It is the first time the M&G Garden has won best in show in M&G Investments’ eight years as title sponsor of the RHS Chelsea Flower Show, which end this year. This is Basson’s first best in show at the RHS Chelsea Flower Show. He has previously won four gold medals in 2013, 2014, 2016, 2017 and a silver gilt in 2012. Crocus built the garden. It was Crocus's 10th best in show and third in succession after Andy Sturgeon/Daily Telegraph in 2016 and Dan Pearson/Laurent Perrier in 2015. The Basson garden included specific plants that are unique to Malta, Darniella melitense, Limonium melitense, Mattiola incana subsp. and the Melitense.
The four show garden golds compare to six in 2016 (out of 17 show gardens), seven in 2015 (15), seven in 2014 (15), 10 in 2013 (15), nine in 2012 (16) and eight in 2011 (17).
Previous best in show winners may return in 2018, with Hortus Loci promising "big hitters" coming back. Andy Sturgeon and Diarmuid Gavin may return, some sources suggested.
Darren Hawkes garden for Maggie's (Linklaters) - image: HW
Andrew Wilson's Breaking Ground garden (Wellington College) - image: HW
Charlotte Harris's garden (Bank of Canada) - image: HW
Kate Gould's City Living garden
Ian Price's Mind Trap garden (id verde)
Lee Bestall's Covent Garden garden, the Tracey Foster-designed Welcome to Yorkshire garden won silver. Chris Beardshaw/Morgan Stanley won silver-gilt as did Patrick Collins' Silk Road garden.
In the plant pavilion, Hillier won a 72nd gold, Raymond Evison won most creative exhibit, Kirstenbosch won the president's award, and Penberth Plants won the diamond jubilee award.
The gardens were judged on Sunday, a day earlier than usual, but medals were revealed on Tuesday.
Meanwhille RHS head of education and learning Sarah Cathcart is leaving for an education role at Longwood Gardens in the USA.