Spencer said many people are saying Brexit will be all fine but that was a premature view, "and Brexit is not in any way resolved".
He added ahead of the Four Oaks Trade show, which will feature more than 200 overseas exhibitors among its 450 stands: "The Dutch are asking what does Brexit mean for us? Will we still be able to sell in the same way? There are more questions than answers at the moment."
He said exchange rates have come back to become comparable to two or three years ago and though they were a "shock at the time" and will be particularly bade for anyone who made a business forecast made on May’s rate, "for most people trading with the Continent, there is no change".
On Plant Variety Rights Spencer said the "assumption is there will be two systems, one for the 27 EU states and one for the UK. And because of the cost of UK rights growers would set up on the Continent and export to the UK, for cutting-raised annuals especially".
The HTA has been pushing for import substitution, but that "is a myth for a lot of plants," Spencer added, "because we don't have the production facilities in the UK and for new varieties breeders say why protect them on both sides of the channel? For trees, yes, for annuals and perennials, it's a disaster."
Spencer said new European plant health regulations will be more than adequate and will have to be adhered by in the UK for imports and exports, but "we need more bodies on the ground from Fera. We will still be bound by European plant health regualtions for imports and exports but any new UK rules will be worthless unless better enforced."
- Follow the latest news and updates from the show in Horticulture Week's Four Oaks LiveBlog.