Blenheim Palace has been named as the Historic House Association Garden of the Year in the 25th year of this prestigious competition. Previous winners — all famous gardens of great repute — include Sudeley Castle, Heale House, West Dean, Barnsley House and Pashley Manor.

The members and friends of the HHA can award up to ten points to each of the 300 eligible gardens they visit, and the award goes to the garden with the most points at the end of the year.

This accolade shows Blenheim in a new light because most, including me, think purely landscape park and Baroque house with historically romantic background.

After all, this is the garden where Winston Churchill proposed to Clemmie as they sheltered from a heavy shower in The Temple of Diana in 1908. It is pure Jane Austen stuff and I was told all about it by my grandmother and shown the building as a child.

I have cycled through the 2,000 acre park when I took part in a road races eons ago and I sometimes meet friends there for a stroll.

The Capability Brown landscape garden is majestic then and this, together with the idea of Queen Anne rewarding the 1st Duke of Marlborough following the Battle of Blenheim in 1704, makes Blenheim nationally important to me. It is the only stately home in England to be given World Heritage Status and the house and grounds deservedly attract lots of international interest.

But when it comes to the gardens, most people are blinkered. We don’t think of Blenheim as a great garden, even though each Duke of Marlborough has put their own stamp on the garden over the centuries.

The 7th Duke, for instance, created a circular rose garden in the mid-19th century and this has very recently been restored.

The 9th Duke added the Water Gardens to the west and the Italianate Garden to the east in the 1860s. The present Duke of Marlborough is no exception. He designed and planted a yew maze 20 years ago. It is situated in the old walled garden originally laid out by the architect Vanbrugh and covers 1.8 acres making it the second largest hedge maze in the world.

It is especially popular with younger children who don’t realise as they scamper through it that the carefully thought out design reflects the first Duke’s military career.

It seems fitting that Blenheim should have a maze once again because romantic tradition records that Henry II’s mistress, the Fair Rosamund, had a house built inside an elaborate maze that was almost impossible to penetrate.

Rosamund bore Henry two sons, William Longspee, who became Earl of Salisbury and Geoffrey who eventually became Lord Chancellor of England. Henry’s wife, the reputedly formidable Queen Eleanor of Aquitaine, was highly jealous of her husband's long-term paramour.

According to legend Queen Eleanor finally managed to peneKtrate the maze, which was shaped like a knot, and then she offered Rosamund a choice between the dagger and poison. Rosamund chose the latter.

It was Ranulf Higden, a 14th century monk of Chester, who first recorded the story of the murder in the maze, although some evidence suggests she died naturally at Godstow Nunnery. The striped rose Rosa mundi, now called Rosa gallica ‘Versicolor’, honours Rosamund’s memory and there is a Rosamund’s Well at Blenheim.

In more recent times the present Duke has restored his father’s private garden. It was planted up in 1952, but became overgrown after his death in 1972.

For 30 years this sleeping beauty of a garden lay untouched. But in 2003 restoration and renewal began and paths were laid, two ponds were cleared and a system was designed to re-circulate the water.

The damper parts of this secret garden look glorious in June and July when irises, hostas, sedges, bog primulas, hemerocallis and Japanese maples are mirrored in two tranquil ponds.

More open areas contain a mixture of herbaceous plants and summer-flowering shrubs. In sheltered places structure is added by tree ferns (Dicksonia antarctica) and hardy exotic palms like Trachycarpus fortunei. Nigel Benfield of Oaktree Nurseries near Witney helped with the restoration and he is not at all surprised at Blenheim’s award. He regularly leads tours of the garden and says: “It is the sheer diversity at Blenheim that has appealed to visitors.”

He hopes that the award will make Blenheim promote their lovely garden much more passionately. The 80 acres of formal gardens are maintained by a dedicated team of nine gardeners. They include Trevor and Hilary Wood, a husband and wife team who share the responsibility of being head gardener together. They have worked at Blenheim for 28 years and have a stable team to help them.

It all makes Blenheim a tremendous asset for those of us living in Oxfordshire and I shall be going this month to enjoy these award-winning gardens with my blinkers off.

The house and grounds are open from mid-February to mid-December - although for the last 6 weeks of their season Blenheim Palace is only open from Wednesday until Sunday. Tickets include access to two thousand acres of stunning parkland, the formal Gardens, free train rides on the miniature train to the Pleasure Gardens and all attractions at the Pleasure Gardens including the Marlborough Maze, Adventure Play Area, the Butterfly House (closed from end of October) the lavender garden, and the "Blenheim Bygones" exhibition. Tickets will also include entrance to the popular ‘Churchills’ Destiny’.