Retailers are likely to buy more cut flowers from overseas after Lincsflora closed on 23 May, industry figures have said.
Former Winchester Growers director Mike Mann is a consultant to the company and has taken over its National Dahlia Collection. He is also chairman of the Horticultural Development Company (HDC) protected ornamentals and outdoor flowers panel.
He said: "It's a worrying thing for the cut-flower industry in general. People are telling me that the pound is working against us, imports are very competitively priced and the high street multiples are looking for the best deal - and with imports suddenly being competitive buying British might be what they'd love to do but they are looking for the best price. It's a concern for the industry as a whole."
Other UK suppliers will pick up some Lincsflora business and some tulip growers have increased production, he added. But "inevitably" importers such as Dutch Flower Group will take market share. To remain competitive the industry needs to adapt robotics and mechanisation, with HDC trials showing promise, he said.
Together with Jon Wheatley, Mann designed a HSBC-sponsored dahlia garden for the RHS Chelsea Flower Show in conjuction with the Mexican government. It will move on to Gardening Scotland and Hampton Court.
Sources say Lincsflora was close to finding a buyer in January only for the deal to fall through. The senior management team has "continued through the consultation to try and find a solution to enable the business to continue. This has not been possible and Lincsflora will close on 23 May 2015."
The company, formed out of Winchester Growers in 2015, supplied millions of tulips, lilies, gladioli, sweet williams and sunflowers to Tesco, Waitrose and Sainsbury's. It employed 118 staff at Nocton and Pinchbeck. Parent company Univeg also operates a £170m fruit business in Lincolnshire.
Winchester Growers and Lincsflora annualised turnover was £45m and the remaining Winchester Growers business is worth an estimated £15m per annum.
At the start of the year, Winchester Growers separated out the daffodil-growing business, which will continue growing as normal. It will focus on production in Cornwall.
Show exhibit - British plants miss deadline
Interflora's RHS Chelsea Flower Show exhibit, which was "intended to represent the best of British but also incorporate British-grown flowers and showcase our 90 years of floristry expertise", ended up with just one British-grown variety on it - stocks from grower Sue Lamb.
The "quintessentially British" garden, which contains a 5m-tall teapot, was intended to feature British-grown peonies, alliums and stocks. However, designer David Ragg said they were not ready in time.
British cut flower campaigner Gill Hodgson said: "They made a big deal about how they were going to do British-grown flowers this year in the run-up to Chelsea but I don't know how hard they've tried to get them."
Choosing a summer flowers theme gave a bad impression of what British-grown flowers are available in May, she added.