Tree experts are stumped over a mystery decline affecting the city's most famous oak tree in Midsummer Place shopping centre.

The once magnificent 150-year-old specimen has been fading gradually since last autumn.

Now, just when it should be in full leaf, it is looking bare and
bedraggled – despite dozens of experts trying to get to the root of the problem.

This week centre manager Martin Hindson revealed the remarkable
catalogue of medical-style remedies, carried out by the finest tree surgeons, that have so far failed. These include:

TONICS to pep up growth
NUTRITION tests to ensure the tree is 'feeding' correctly.
ENDOSCOPY-style camera investigations of drains to test the water supply.
MASSAGE – in the form of vibrating probes to oxygenate the surrounding soil.
BIOPSIES of bark and leaf samples to test for diseases.
AMPUTATION of some branches in the hope that it will strengthen the rest of the tree.

He said: "We've ruled out all the obvious diseases and we've brought in four different sets of experts.

"But the tree is still not looking good.

"It is a real worry – the last thing in the world we want is for this famous oak to die."

He first noticed the decline last summer, but some observers say it sped up after the city's concrete cows were moved to a permanent grazing spot underneath the branches.

"There is no connection. There's no way the cows can affect the tree," said Martin.

The mighty specimen was incorporated into the new shopping building – at considerable expense – to form a striking centrepiece in Oak Court.

It is subject to a Tree Preservation Order.

But, should the worst happen, history could live on.

For, thanks to some local schoolchildren, a branch of the tree's family still exists a few miles away.

The pupils visited Oak Court three years ago and picked up acorns, which they set into pots.

The resulting seedlings were set in Campbell Park where they are now healthy young saplings.

"This is reassuring," said Martin.

"But we are still hoping our tree will survive.

"We will certainly continue to do everything we possibly can to save it."

Have you got any idea what's going on? Let us have your ideas, email us on editorial@mkcitizen.co.uk