It is Valentine’s Day in Cambridge and, at a market stall near King’s College, Nicki Lark is cheerfully selling bouquets of roses, daffodils and tulips to young lovers in the sunshine. But, behind her smiles, she is worried.

She fears that, like many other UK businesses that rely heavily on imports from Europe, this family-run florist, which has operated in the city’s market square for the past 60 years, will have to increase its prices in the event of a no-deal Brexit – and might struggle to survive.

“We do try to source flowers locally, but most of what we sell is imported. After Brexit there could be a big, big difference in the prices of what we buy.” If the cost of imports does rise, it will have a knock-on effect on the prices she will charge, she says. “I’d like to think we’ll still be here, but I don’t think we’ll have the volume of flowers we have today, and our customers won’t have as much choice.”

About 80% of the flowers sold in the UK are imported from the Netherlands which, in turn imports and auctions off flowers from across the world, according to the British Flower Association (BFA), the trade association for independent florists. Its chairman, Brian Wills-Pope, predicts that, in the worst-case scenario, following a no-deal Brexit the UK’s 7,000 florists would have 50% fewer fresh flowers to sell.

“Florists would have to be inventive,” he says. “I think in that scenario British growers would increase the amount of flowers available to florists. A lot of these flowers currently go to supermarkets.”

His main concern is border control and flowers getting stuck in transit. “We can’t stockpile like other industries, because flowers are so perishable. The exchange rate also obviously affects us.”

But he is hopeful that the Dutch will get their flowers across, no matter what – even if it takes much longer. “The Dutch are not going to want to stop exporting £800m-£900m of flowers to us. They will find a way.”

Delays will, however, make it more difficult for florists to plan deliveries and that could lead to redundancies. “I couldn’t say florists will definitely go out of business, but there might be a reduction in staff numbers if there were fewer deliveries.”

At the Flower House, an independent florist supplying many Cambridge colleges, Petrena Campbell is on the phone arranging a last-minute Valentine’s Day delivery. Chococino roses, green chrysanthemums, hyacinths, flax flowers, clematis and anemones line the shelves, filling the air with scent, and a dozen bouquets of red roses are waiting for delivery by the door. A student with blue hair enters and buys a £6 cactus.

Petrena Campbell at The Flower House says the divide between florists and supermarkets would grow. Photograph: Sophia Evans/The Observer

Campbell says she, too, is worried about a cliff-edge Brexit. “Prices probably will go up, and that will make competing with supermarkets harder. They can buy massive amounts of flowers and keep prices down.High street florists can’t compete.”

She buys online from auctions in the Netherlands and, like Wills-Pope, worries about border delays. “Our suppliers transport flowers in really good time at the moment. They travel overnight and are here next day. That allows us to react when somebody wants to send flowers at short notice.”

Campbell fears she may no longer be able to offer this level of service after Brexit, but thinks it won’t make much difference to her wealthiest customers. “I wish the government would just get on with it. Over time, if we can’t get flowers in next day, people will adapt – if they are fortunate enough to be able to spend a reasonable amount on flowers.” But she thinks that small florists might no longer cater so well for lower-income customers.

Then the divide between supermarkets and florists would grow, she predicts. “What we do will become more exclusive. Fewer people will be able to afford bespoke arrangements.”

Online florist Bloom & Wild is one of the UK’s fastest-growing businesses. It has 80 employees and couriers hundreds of thousands of flowers each week to customers in the UK, Ireland, France and Germany.

Chief executive Aron Gelbard says 90% of Bloom & Wild flowers are grown overseas, and the uncertainty of Brexit is already having an impact on the business. “We don’t know whether to start putting no-deal plans in place or not. As a small business, we can’t really run two parallel scenarios. Not knowing whether or not there will be a deal, this close to 29 March, is a real challenge.”

He is concerned that border delays will make it harder both for flowers to be brought into the UK and for flowers to be delivered on time. “A lot of our flowers are gifts for occasions like birthdays. If our deliveries are held up at customs, say between the UK and Ireland, we would let customers down. We can try to mitigate that by sending them a day early, but people don’t really want flowers to arrive the day before a special occasion.”

He also worries what will happen to his business if the pound substantially weakens against the euro. “Our costs will increase, and then there may be tariffs on top of that.”

Being forced to source more flowers from UK growers would not be ideal. “We do try but, for many flowers, there isn’t the variety of stock, or it’s more expensive. Plus the impact on the environment of heating greenhouses in the British winter is worse than the impact of growing a flower in a naturally warm climate and flying it over.”In London, Sharon Crane, a florist at The Gated Garden, Borough Market is more laid back about what might happen in March.

“None of the suppliers that I deal with has expressed any concern at the moment. The Dutch are very good, they will import even if they have to go further up into England and not use the channel.”

She says she will change the stall to feature more British flowers come the spring anyway and this will mitigate the potential problem of pricier imports - at leas for a while.

“British plants have a time,” she says. “We change the stall to British, probably around end of April or early May, the start of the bedding season. If you know your English, all bedding should be English, you should not be buying Dutch bedding. So, we just roll with bedding and that will supply us right through September-October.”