The new market is located along Nine Elms Lane in Vauxhall, south London from the current market. There is covered parking, 500 lux bright lights and a café.
Existing market wholesalers, as well as a dozen contract florists have moved to the new site. Wholesalers were due to move over the weekend and some were due to be open for trading on Saturday.
The old market opened 40 years ago and has now been redeveloped. The main area is open-plan and conditioned to 14°C. There are self contained units with shop fronts at the front and the back of the Flower Hall.
Among stand holders will be Evergreen Exteriors, L Mills, Pratley and Dennis Edwards.
Bedding specialist L Mills' Bob Colley said: "It's lighter and brighter. There's nothing to stop us from selling more. But trade is what it is."
Colley said thanks to brighter March weather, after a "proper winter", the firm had seen a better start for sales. He said the hellebore season had been better this year.
Florist Pip Bensley, formerly plant buyer at Hillier, said: "The market is moving forward with a more professional approach. There's been a lot of scepticism so it's nice to see it coming to fruition. This is very much the London market, primarily for high-end florists. There's an amazing range and good specialists."
But she said British flowers were not easy to identify and sellers were "not good at shouting about" provenance.
Bensley said she uses local growers in Hampshire and many English growers, small and large, cut out the middleman.
She said Florismart and FloraBritain were helping florists order online, with a range of grades and by including British growers of varying sizes.
Bensley said she visits Covent Garden every couple of months, partly to study trends, and said they were moving away from "the footballer's wedding look" of masses of hydrangeas and roses to a "more bohemian, looser, garden-y look" that was "quirky and interesting".
She said more scent on roses and sweetpeas and flowers such as fritilleries stood out. Bensely also said the market was good for finding unusual pot plants and added value indoor plants, such as those with hessian wraps on them.
Celebrity floral designer Simon Lycett said: "This is a great space and a really positive sign sending a really powerful message that buying flowers from wholesale markets is really still very important."
He said it was easy for florists to buy direct from Holland or via Dutch vans but the market was "literally pick of the bunch".
Pratley's Mick Wait, the only UK specialist cut flower grower at Covent Garden, said there were so many other outlets now that there were fewer loyal customers remaining. He had Guernsey alstromerias, UK daffodils, irises and tulips among flowers on offer. "I'm the only one still flying the flag," he added.
Meanwhile, the British Florist Association is proud to announce that it will be creating a floral stand feature at the RHS Chelsea Flower Show this May as a highlight of its 100th anniversary celebrations.
The stand ‘The British Florist Association at 100’ will be staged in the heart of the floristry zone of Chelsea’s Great Pavilion, and has been designed by floristry students at BFA Member College, Moreton Morell in Warwickshire, led by its award-winning tutors Jane Benefield and Laura Leong.