A Duchess has been granted permission to grow cannabis, cocaine and opium in her gardens -- in a bid to teach youngsters about the dangers of the drugs.

The Home Office has granted a licence to grow cannabis and the caco plant, from which cocaine is made, at the Duchess of Northumberland's dream Alnwick Garden.

The Alnwick Garden charity applied to the Home Secretary for a licence to grow the plants for special educational purposes more than seven months ago.

The drugs will be grown alongside more than 50 dangerous plants in the country's largest ever public Poison Garden.

Hallucinogenic magic mushrooms, opium poppies and seeds will also be grown.

The Poison Garden has been designed by Peter Virtz from Belgium in the shape of flames to illustrate its "danger, intrigue and excitement."

Although it is almost completed and will open this winter many of the plants will not be growing until the Spring.

A spokesman for the Alnwick Garden said: "This is brilliant news from the Home Office. It is the first public poison garden of this size. "The abuse of drugs is a very important issue and the charity has been working with drug awareness groups in the region to provide a new avenue to help people talk about drug abuse outside of the classroom.

"The new Poison Garden shows that the garden is more than just a beautiful place. It is more than just a tourist attraction. It can have a transformational impact on the community.

"The Duchess, whose vision it was to create this, saw that children didn't want to just see a pretty place and don't want to just hear about herbal remedies. This will grab their attention to learn about dangerous and poisonous plants. "The most dangerous plants will be grown in cages and there will be a lot of security.

"We hope the garden will be a useful tool for drug awareness agencies to help engage young people."

Castor oil plants, used to produce the deadly nerve agent Ricin, are on the cards, as is a whole host of other more common herbs, plants and weeds such as foxglove, tobacco and wild lettuce, which induces coma.

A Home Office spokeswoman said: "Alnwick has been granted a licence to grow cannabis and caco for special educational purposes

"All varieties of cannabis are controlled under the misuse of Drugs Act 1971 and a Home Office licence is required to grow it. It is also been so designated under the act that a licence can only be issued for the purpose of research or other special purposes if the Home Secretary is of the opinion that it would be in the public interest to do so."

The plants for the Poison Garden were on a list suggested by garden historian, author and award-winning broadcaster Caroline Holmes.

She has worked as consultant for the Poison Garden. She said: "You will not be able to come in and harvest your own cannabis. That was my great, great fear."

Access to the walled garden will be strictly controlled with visitors escorted by marshals.

Ian August, Alnwick Garden liaison officer, has said: "At the end of the day what we are doing is a planting scheme within the garden and the theme will be poisonous plants.

"The whole brief behind this is making people, and in particular the younger generation, aware of how dangerous these plants can be, but there is an historical element to this as well."

The garden project, which is now being run by a trust, was begun by the Duchess of Northumberland, who dreamed up the plan to transform an old, unused walled garden next to Alnwick Castle. It is due to be completed by 2008.