Garden and greenhouse enthusiasts with an English oak growing on their land have been told to watch out for a new threat.
The species is under attack from a little-known infection known as acute oak decline (AOD), which can kill a tree in less than five years.
First discovered 13 years ago, the disease attacks the tree from the inside, causing it to bleed dark fluid through the bark, according to the Royal Horticultural Society (RHS).
The latter stages of the infection see the canopy thin out and branches begin to die away.
It is believed that the main cause of AOD is a bacteria, which has recently been isolated by researchers.
Woodland Heritages Peter Goodwin told the RHS that the issue could be even more devastating to the British landscape than Dutch Elm Disease and that more should be done to help solve it.
"We cant afford a repetition of what happened then. Action is needed now," he said.
Meanwhile, the RHS recently reported that a secret garden in Monmouth is set to be restored to its former glory.