One of the UK's leading commercial nurseries has told how it had to stop supplying plants to Northern Ireland after new Brexit restrictions came into play in January.
Before the UK left the EU, Johnsons of Whixley sold £500,000 of plants to Northern Ireland customers every year.
The company said new and impractical restrictions had hampered long-standing trading relationships.
Plants which originate from a bare root young plant, or those that have had any contact with the soil, even if container grown, are considered a risk because of the likely legacy of soil residue, which has the potential to carry pathogens or nematodes, Johnsons said.
While not impossible, soil residue removal is impractical and would defeat the point of rootballing and containerisation.
Long-standing customers of Johnsons and many other nurseries are left with no choice but to go directly to EU suppliers because there are no restrictions on legacy soil residue between EU members or affiliates in the guise of Northern Ireland.
Johnsons head of production and procurement Jonathan Whittemore said: "This legislation penalises UK growers and gives an immediate competitive advantage to EU suppliers, who may go on to monopolise supply into an existing part of the UK at the expense of our business and the wider industry."