He says post-Brexit the question will be whether there is any scope for export. "The problem the UK has got is that it has an open market for export now into Europe and they don't use it much. It's limited to when you have a brand or genetics that you want to get into the wider world."
UK plant exports remain at £50m, with imports at more than £1bn, says Defra, despite post-Brexit vote exchange rates favouring export over import.
Briercliffe points out that trade barriers are not the issue to overcome. "The big issue is plant health. There are countries with big opportunities like China but getting things to these countries is a real challenge. The big issue with global trade for the future and where the UK could make things more awkward or not is with Brexit.
"China is a massively growing market. It mostly services its own market but there is big potential to supply from outside, but getting plants in is massively difficult because of customs and bureaucratic restrictions there."
He says just getting an official to sign a form can be difficult. AIPH has a congress in Taiwan in September on ornamental horticulture in south-east Asia and there is a horticulture expo in Beijing in 2019, which is seeking UK involvement.
In May, a Chinese delegation visited Briercliffe and reported progress on expo planning, construction and publicity, met the RHS at the Chelsea Flower Show and spoke with UK Government representatives about the exhibition. In 2016 there was an Expo in Antalya in which the UK participated, with the idea that it might hold its own event, which is one of the ornamental round table's 12 "asks" of Government.
Some 27 countries and international organisations have provided written confirmation of their intention to attend Beijing Expo 2019. HTA horticulture head Raoul Curtis-Machin says the Expo is being discussed through the horticulture round table group and other organisations, with Defra and the Beijing organisers, adding: "It could be an exciting opportunity for the industry post-Brexit." Briercliffe says: "Businesses are trying and if they can find a solution it could open up an important market."
Dutch auction house FloraHolland is trying to develop online cut flower sales to China and Turkey in particular, but the UK is not a large producer of cut flowers so is not involved. Briercliffe suggests that the UK could get more involved in growing overseas horticulture by exporting expertise. The Dutch are good at this and there is plenty on offer in the UK that could benefit developing countries, he adds.
Plants for Europe's Graham Spencer wonders whether potential for UK exporters in China is that big because Chinese city dwellers tend to live in apartments without gardens. There are easier export markets "20 miles away across the Channel", he notes.
The breeders' agent uses tissue culture labs in China and sees opportunities for plant breeders to export genetics to China, providing you can get the plants there and someone to grow them there. He says Chinese commerce works very much on personal relationships, which could exclude smaller UK businesses that may not be able to justify the number of trips to the far east needed to build them up.
Spencer says there is an obvious easier market "on the doorstep". Few British growers were at Salon du Végétal in France in June, but Fairweather's of Hampshire had a strong show with its specialist agapanthus offer.
Fairweather's Sharon Lowndes says the show saw good sales but it is "not a quick process" to crack the market. There used to be more UK exporters at the show but you need a big name, such as David Austin Roses, or a strong niche to make an impact, she adds. Fairweather's trades in euros and has been working on building European business for several years, including at shows such as IPM in Germany. On Chinese exports, Lowndes says: "not at the moment".