Jersey and Guernsey governments took the fight against the scrapping of LVCR to the UK High Court, but lost but the States may still appeal on April 2 or 3.
The Jersey and Guernsey governments said hundreds of jobs across both islands were at risk.
LVCR meant no VAT was charged on goods under £15, such as bedding plants, when sent to the UK from outside of the European Union.
Mainland-based grower Derek Jarman of Hayloft Plants, who has campaigned for the end of LVCR, said: "The Channel Islands who now compete with the mainland on a level playing field rather than with a 20% advantage."
Horticulture Week 30 March found that Thompson & Morgan had looked at Switzwerland as a non-EU country to import form VAT-free, but dismissed the idea as logistically to expensive.
Boley Smillie, chief executive of Guernsey Post, said:
"To put the price increase into perspective, the loss of LVCR will reduce our profit by £3.7m over the next 12 months."