The inaugural meeting, held on March 13, will bring between 200 and 250 people from as far afield as Teeside and Cumbria to Alnwick to discuss the event, jointly hosted by Alnwick District Council and The Alnwick Garden.
The initial meeting is set to be held at the Northumberland Hall and the presentation of prize-winners is expected to be held at the Garden's newest addition, the Pavilion.
Tom Pattinson, chairman of Alnwick in Bloom, welcomed the news.
"It's quite a high profile event and brings the dignitaries with chains of office from all over the region," he said.
"It's such a marvellous opportunity for Alnwick to show itself off and sell itself to all of the members."
Mr Pattinson said it is the first time the meeting has been held in the town since the Alnwick committee formed in 1982.
Coun Eileen Blakey, committee member and Alnwick town councillor, added: "It's tremendous for the town and a great honour. I'm so excited about it. We will have to have a little litter pick before the big spring clean at the beginning of March to tidy up in time for the meeting,"
Gazette editor and committee member Paul Larkin has also added his support.
He said: "The Gazette will be starting a campaign to reduce litter before the judging of Northumbria in Bloom. Not only do we want to give the town the best chance of winning, we also want to free our streets of this nuisance."
Coun John Rutherford, chairman of the district council, said: "We are delighted to be hosts of such a prestigious event.
"Northumbria in Bloom epitomises what is so good about our society. It brings together communities and the outstanding work of so many dedicated volunteers, generates a huge amount of local pride and spirit in towns and villages across the North East."
John Lovett, chairman of Alnwick Garden Enterprises, said: "For the coming season, we will have our new Pavilion and Visitor Centre so it is very pleasing for us to be able to host this event and support the town. We really hope it will be enormously successful."