(Nectria cinnabarina)
Coral spot is a fungal disease that causes woody stems and branches to die back and produces tell-tale small, coral-pink/orangey raised pustules on affected growth.
Nectria cinnabarina is very common and initially grows saprophytically (feeding on already dead organic material) on dead or dying wood, including dead stubs left after incorrect pruning, wounds or growth damaged by frost or other conditions. It then moves into living wood, causing further dieback.
After causing dieback, the fungus forms its pustules, which produce spores that spread the disease further. These need damp conditions and are mainly dispersed by wind-blown rain and rain splash.
Try to keep trees, shrubs and other woody plants growing as strongly as possible to help them fight off disease attacks. Early identification of affected stems and branches and their removal will help reduce spread within the plant and to other plants.
Prune out any infected growth as soon as you see it, cutting back to healthy, unaffected wood. Dispose of the prunings, either by burning or put them in the council’s green waste bin. Don’t leave dead wood lying around.
Ideally, as rain aids in the dispersal of spores, always aim to prune in dry weather. Always prune back to growth points or leaf nodes (joints) and cut large branches just beyond the collar (the ring of swelling around the base of branches). This ensures the pruning wounds heal the most quickly. If further dieback occurs after pruning, cut out the affected growth to prevent further infection.
Unfortunately, there are no fungicides available to control coral spot.
Applying Vitax Medo (a wound paint) over cut surfaces, especially during damp weather or if infection is known to be widespread, may help prevent infection. But don’t use wound paints as a matter of routine, as they interfere with the plant’s natural healing processes and can provide a more suitable environment for fungal and bacterial rots to proliferate.
Keep plants growing as strongly as possible to reduce stress. This may include watering during very dry weather and feeding regularly.
Always prune correctly and at the correct time of year for the plant in question.
