THE Prince of Wales will officially open the first phase of a multi-million pound garden development next week.

Although it has only been open to the public since last October, it is estimated that Alnwick Garden will have attracted more than 260,000 visitors from all over the world by its first birthday.

It already has a 9,000-member friends group, of whom the first 2,000 to respond to invitations will join Prince Charles for the first phase opening, on Monday.

The Prince of Wales, who is the garden's patron, will embark on a one-and-a-half hour tour with the Duchess of Northumberland, who has been instrumental in bringing work on the first stage to fruition.

He will meet the garden's designers, the Alnwick Garden team, sponsors, and others who have played a major role in the project.

During the ceremony, it is expected that plans will be announced to begin fundraising for further stages of the garden.

They will comprise seven themed gardens, including a serpent garden, poison garden, labyrinth, spiral and a garden of the senses, as well as a pavilion housing a restaurant and conference facilities.

The duchess has recently applied for planning permission for the world's biggest tree house, which would overlook Alnwick Garden and serve as an education centre.

Ian August, garden project director, said: "We have been looking forward to this day for some time.

"It will be the icing on the cake for those who care so much about this project and have been loyally supporting it since work was completed on the first phase last year.

"His Royal Highness has taken a keen interest in progress of the garden and I know he will be fascinated to see what has been achieved."

The 12-acre garden, which has won a civil engineering award and a Civic Trust award, will be closed to the public until 2pm next Monday.