Covent Garden Market Authority (CGMA) business development and support director Helen Evans said the only option was to sell land to invest in the buildings. The £2bn redevelopment will see developers St Modwen and Vinci build new markets and get surplus land for mixed-use developments in return.
Evans said the £51m annual turnover market was in "severe decline" a decade ago but has now found its niche. She added that since the flower suppliers moved from their original Covent Garden site their businesses have changed considerably because of supermarkets taking over much of the mass of cut-flower retail sales.
Transactions at the market are now "specialised" and "niche" sales to florists who are designing bouquets for events after supermarkets "commoditised" cut flowers, she explained. Evans praised supermarkets for broadening the market but criticised cheap daffodil offers and the trend by supermarkets to use offers on fresh produce to "hook the consumer".
"The bulk" of product sold in the UK remains Dutch and "no one knows the implications" of leaving the EU, she added, saying she believes traders' hearts are telling them to leave but their heads are telling them to stay in Europe.
Evans said demand has risen recently for British-grown flowers but issues include volumes and lack of economies of scale. On marketing, she said the end of the UK Horticulture stand at the RHS Chelsea Flower Show was a "real shame". CGMA has an exhibit at this May's show to promote the market's move to its new home.
The future of British-grown is in co-operation, said Evans. "The only way the cut-flower industry in this country is going to grow is by banding together." She used FloraBritain as an example.
Pratley owner Mick Waite said high-end florists are now a big customer for his largely British- grown offer of stocks, ranunculus, tulips and many other varieties from growers such as LF Geater and Smith & Munson. He added that he believes importers have unfair advantages. "I will be voting out of Europe because the Dutch lorries drive around shops delivering without declaring for tax at our ports. If we were out of Europe they would have to pay tax on what is on their lorries."
JW Tyrrell's William and Sam Tyrell said promotions such as Red Tractor help but "there has been very little on the floriculture side", though British Flowers Week (13-19 June) is useful.
Bobby Cooley of L Mills said his bedding offer will "always have a place" in the market but it is now a "cottage industry". He is against leaving Europe because "it won't stop lorries driving through the tunnel" and "as Churchill said, jaw is better than war". Cooley said he is "an outlet" now for the nursery, with most sales going direct, in common with most of the industry, where online orders and direct deliveries are the norm.
Zest Flowers' Graeme Diplock said the better quality of British flowers creates demand, though all-year-round supply is impossible. He added that leaving Europe would be a "worry" and called the new building a "positive change".