With a new ratings list due to take effect from 1 April 2017, a change in approach is on the way from the Valuations Office Agency (VOA) on its rating of horticultural businesses that grow their crops mainly in buildings or glasshouses but do not bring these crops on to their final maturity.
A 2015 Court of Appeal verdict against a mushroom grower decided that those with "nursery grounds" whose plants leave the premises before they are mature and there is little connected use of open land in the growing cycle have to pay business rates. But the NFU, which supported the mushroom grower's case in court, argued that the VOA's "extreme approach" is "contradictory to current guidance".
Fairweather said: "I hope the industry unites to ensure the precedent that has been set by this court case is overturned. We're young plant growers and I have no idea how ratings officers would ensure how the balance of space between outside and inside should be rateable. Some crops spend all their lives inside and some spend part of their lives outside."
He added that the law is "too complicated as it stands" and needs re-interpreting. "If that level of charge is going to applied it will have a decimating impact on young plant production in this country and on the whole supply chain."
Fairweather said he would like to see a campaign to get the plan overturned and pointed out that he has written to the HTA and his MP about it. "We have to campaign. We don't know whether or when they will be knocking on your door. I think it's going to be devastating if it is applied." He said many young plant propagators have no outdoor growing area so may be hardest hit.
On who will be billed, HMRC said: "It depends on whether we know about them or not. The Court of Appeal decided nursery grounds/buildings aren't exempt, so when we become aware we will bring in the relevant rate, as we're updating lists all the while. Bedding, as far as I understand, is included. It's nursery grounds in buildings so that sounds like them. If anyone has any doubts, see www.voa.gov.uk to check rateable value and liability by postcode."
Bills could be backdated to 1 April 2015, HMRC added, but it does not know how much could be raised or how many growers could be involved.
NFU acting chief horticulture adviser Chris Hartfield said the NFU is "in the process of gathering and building evidence from potentially affected grower businesses at the moment".
HTA horticulture head Raoul Curtis-Machin said: "There seems to be two stands to this one - the law and the interpretation of the law. Because this is law, we will have to wait for a legislative opportunity to change it. This could come in the post-Brexit negotiations about the future of UK agriculture."
He added: "We agree with the NFU's opinion that the interpretation is harsh and we will work with individual growers to encourage a common sense, modern approach. This is potentially very worrying for growers because the VOA's draconian interpretations and definitions could bring them into paying business rates where they haven't had to before. We would urge concerned growers to follow the NFU advice and contact their helplines."
Rates were "discussed at length" at an HTA ornamentals committee meeting last month, said Curtis-Machin. "The general feeling was that liner, plug and young plant producers are most at risk of rates category changes. The definitions are out of date but it's a complex business to change legislation. Along with the NFU, HTA will offer help to any individual members where possible because it looks as if local interpretation will be key."