Coral Spot (Nectria cinnabarina)

Alternative name – Nectria Twig Blight

Plants/trees Affected

Magnolias, Acers, fruit trees, currant bushes & gooseberry bushes

Symptoms

Coral spot is a small cushion like, poisonous fungus, no bigger than 2mm, which is coral/pink in colour.  This fungus appears on dead stems and branches, usually in the winter months (October to December).  It can also be found on fences, wooden furniture and old wooden supports such as pea sticks.

Causes

This disease is created by a fungus, large numbers of spores can be produced throughout the year and enters the plant through wounds caused by pruning, frost or possibly storm damage.  The branches are usually dead by the time you see the coral spot but it can spread to living areas which will then cause wilting and eventually dieback.

Coral spot is not usually a killer disease on its’ own, and only becomes fatal if the plant is young and not fully established or suffering from another debilitating conditions such as drought stress or root disease. However if this fungus should reach the trunk of a plant it may die.

Prevention

Treat any infected fences and wooden furniture with fungicide and if the disease is present in the garden, do not leave dead branches and twigs lying around. Do not leave snags when pruning, prune to just above a bud.
 

Treatment

• Prune out all dead wood but only in dry weather.
• Any branches affected by coral spot should be cut out at least 15cm into healthy tissue.
• Do not compost any of the diseased branches (remove or burn).
• There are two schools of thought on sealing the wound. The first is to treat it with a protective wound dressing like Arbex 'Seal and Heal'. The second is not to treat the cut at all as you may just be sealing in the spores you are trying to remove...

• You may use a fungicide like thiophanate-methyl to treat the infected plant and repeat after 3 weeks but success is not guarenteed... more of a bolt and braces approach!
• Mulch the affected plant/tree with organic material and feed with a good all round fertilizer e.g. fish, blood & bone.