In 1651, following the Battle of Worcester, the future King Charles II hid from his pursuers in a tree now known as the Royal Oak.

''For over 200 years the king's birthday was celebrated by wearing a sprig of oak leaves in remembrance,'' Stephen Alegria, executive manager of the National Arboretum, said.

The species chosen for the English oak Prince William and his wife, Catherine, will plant is known for its long life, with some known to have grown for more than 1000 years.

''The reason the English oak was chosen in the planning was because it represents strength and endurance and, of course, has a long association with England,'' Mr Alegria said.

''This is a very impressive tree when it is fully grown.''

English oaks typically have a low branch canopy that can measure up to 20 metres wide.

The site for the royal tree was carefully chosen to be easily accessible and to shade children playing in the Pod Playground.

The gardening theme will continue on Friday with the royals set to plant an Aleppo pine to replace the Lone Pine at the Australian War Memorial.

The current pine was planted in 1934 by Prince Henry, Duke of Gloucester. The seed of the tree came from a cone collected by an Anzac soldier after the capture of Lone Pine ridge in Gallipoli in 1915.

At the time the tree was surrounded by an almost empty paddock and came to be known as the Lone Pine.

But in 2008 the tree was damaged by storms, and in 2012 it dropped another limb, forcing arborists to take steps to seal its trunk and thin the canopy to reduce the effects of wind on the 80-year-old tree.

There are no immediate plans to remove the Lone Pine although arborists have told the war memorial that the tree is in poor health and close to death.

A war memorial spokesman said the Duke and Duchess would be planting seeds from the same germination as the Lone Pine to ensure a replacement exists when the pine dies.

The spokesman said there are no plans yet for the Lone Pine's wood once it is removed.