Each year the Bishop of Norwich and his wife open their garden in aid of charity – raising a record £18,000 in 2012. As this year's events get under way, TARA GREAVES gets a guided tour from head gardener Simon Gaches.

For more than 900 years there has been a garden belonging to the Bishops of Norwich nestled in the heart of the city.

Tucked away behind the magnificent Norman cathedral, the current four-acre incarnation is a pleasant mix of the traditional and the new, which creates a tranquil and inspiring space away from the hustle and bustle.

While in the 1940s up to 15 gardeners were employed to tend its needs, it is now the task of one full- time head gardener, his part-time assistant and a band of willing volunteers – and what a job they do.

Each year, thousands of people flock through the grand entrance during a series of charity open events, hosted by the Bishop of Norwich, the Rt Rev Graham James, and his wife, Julie.

Visitors take the opportunity to admire the formal and informal gardens together with unique views of the cathedral, including the stonework on the North Transept which can only be seen from the garden.

Head gardener Simon Gaches, 42, is a man clearly very happy in his role who takes great pride in showing off the garden.

Usually Simon has favourite parts depending on the season, such as the herbaceous borders – one of the central features – in June.

'We are about three weeks behind this year because of the cold winter so I think everything will come at once,' he said.

It is his 19th year caring for the garden, having previously been in hotel management before retraining at Easton College.

He has a particular passion for plants from the southern hemisphere which he has been able to indulge, including a rare Euphorbia x pasteurii Phramptons Patty which smells like honey when it is in bloom.

'Native plants have some interest but times have changed and people want to see more exciting plants and I like to be the one to be the first with them and show them off,' he said.

'For the first six or seven years I was here, I was basically tidying up and bringing the garden, which was private then, to a high standard. When Bishop Graham and his wife came they allowed me free rein, which has been brilliant. The chance to make my mark on something that has been here as long as this, while still preserving the history and values, is amazing.'

As well as a wildflower labyrinth which has at its centre a 350 year old pear tree and surrounded by 150-year-old yew hedges, there is also the second largest London plane tree in Norfolk and a hebe planted from a sprig taken from Queen Victoria's wedding bouquet in 1840.

Over the past few years, Simon has transformed areas of the garden including adding a bamboo walk and various enhancements, such as box hedges around the rose beds, and separating the organic kitchen garden from the work area with a hornbeam hedge.

'I get a real buzz from the open gardens. It's the one time of the year when people come in and appreciate and enjoy the work we have done,' he said.

This year, an article about the garden has made it into the Royal Horticultural Society's monthly magazine, which has delighted Simon.

The father of two boys, Joshua, 11, and Isaac, five, lives on site and says his children love being in the garden with him.

He also has a good working relationship with his assistant, fellow Easton College graduate Will Gates.

The Rev Simon Ward, bishop's chaplain, said: 'The charity open gardens are really important to the bishop and Mrs James both for the opportunity to fund raise for groups and organisations and also just to see lots of people coming to enjoy it. It is a gift that deserves to be enjoyed.

'The open events have continued to grow. This is the fifth summer I have been here and it just seems that the amount raised keeps going up. I think people appreciate that all the money raised goes to the charity.'