Ask John Negus John has been answering reader queries for 50 years
Is there any way of saving our tree?
Q Iâve noticed over the past five/six weeks that my conifer has become ill-looking. Have you any idea what it is and if it can be cured?
Gill Smithers (via email)
A I am sorry that your once splendid cypress is dying. The usual cause is honey fungus, a disease that blocks the plantâs food and water canals.
Check to see if this fungus is responsible by using a three-pronged cultivator or garden fork to loosen soil around the tree. If stretchy black bootlace-like rhizomorphs are visible, blame this disease.
If not, then the problem is almost certainly phytophthora, another fungus that attacks the cambium, where growth occurs. In this instance, it causes the middle of a shoot to turn brown and die.
Cut a stem in half with secateurs to see if its centre is discoloured. Sadly, there is no cure for either disease.
One option is to replace it with another
