Croke Park stadium director Peter McKenna told the Pat Kenny show on Newstalk this week that Brexit could add hundreds of thousands of euros in grass costs every year.
McKenna explained that the grass on the pitch dies after being covered for each concert, with Croke Park licensed to organise up to three such events every year.
"It's harvested. There is a farm in Lincolnshire that specialises in this," he explained.
It's an expensive part of the operation
Replacement grass is cut to a depth of one inch and shipped to Dublin. The farm also grows grass for pitches at Real Madrid's Santiago Bernabéu Stadium and Wembley in London.
"It's an expensive part of the operation," McKenna said, because the summer concert and GAA championship seasons are in full swing in Croke Park at the same time. Other European arenas tend to host concert during the summer soccer and rugby break, which gives grass time to regrow.
"The indications are that there could be something like a 20% surcharge on agricultural products;" McKenna said. "That would put 20% on taking our pitch in, which would probably add €100,000 to the cost of replacing pitches post-concerts."
In answer to a listener asking for some of the discarded turf, McKenna said: "It's pretty macerated when it's taken up, but if they want to come to Croke Park I'd be more than happy to give them some of the grass." Used grass is otherwise used by Dublin City Council in public parks.
Farmers looking to graze animals on Croker grass know where to go after the U2 gig next weekend.