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 will move to the new site.
Wholesalers will move over the weekend 1-2 April and some of them will be open for trading on Saturday 1 April.
Among stand holders will be Evergreen Exteriors, L Mills, Pratley and Dennis Edwards.
There will be a Chelsea Flower Show Covent Garden-themed garden at this year's event, designed by Lee Bestall.