Advice
RHS Help & Advice
Coral spot (Nectria cinnabarina)
Susceptible plants
Many including currants and gooseberries (Ribes species), maples (Acer species), Elaeagnus, Magnolia species and hybrids.
Symptoms
Coral-pink cushion-like bodies develop on dead stems and branches of a wide range of broad-leaved fruit and ornamental fruit trees (see right). As the fungus is a common saprophyte, it is also frequently seen on wooden structures (fences and furniture), woody debris and old pea sticks (particularly those of hazel) in autumn and winter.
Cause
The coral spot fungus, Nectria cinnabarina, is spread by vast numbers of spores which are produced throughout the year. The fungus enters plants through wounds caused by pruning or other damage (frost or storms, for example). By the time the symptoms appear the wood is usually dead. However, coral spot can spread back to living tissue, causing dieback. If it enters the main trunk of susceptible plants they may well die.
Coral spot is usually a weak parasite, and seldom becomes troublesome except on plants suffering from some debilitating condition such as drought stress or root disease, or on newly planted trees or shrubs that are not yet fully established. For this reason, if a plant is badly attacked by coral spot, the possibility of an underlying cause of this nature should be considered.
Prevention
- Prune out all dead shoots and branches.
- Any shoot or branch affected by coral spot should be cut back to clean healthy tissue well below the dead or diseased wood. Use a protective wound dressing (e.g. Medo or Bio Arbrex) on larger wounds.
- Prune only in dry weather.
- Collect any woody plant debris from the garden and remove or burn.
- Mulch trees and shrubs with organic matter especially on light soils, and feed with a complete fertiliser such as fish, blood and bone, or Growmore, to maintain vigour.