Coral spot fungus grows on dead wood, and spreads through wind-blown spores to infect and kill living woody plants. It can often he seen on old pea sticks. Any wood affected by this disease should be destroyed.
The disease is found in many trees and woody shrubs, particularly maples, magnolias, figs and redcurrants. It’s caused by a fungus which breeds on dead wood. Airborne spores infect trees through dead twigs or branches, pruning cuts or wounds, especially in early spring. Sometimes the spores can get a hold through the base when plants are growing in damp conditions such as dense grass. The first visible sign of the disease is the appearance of coral-red, spore-filled pustules on diseased branches, which begin to die back. Sometimes the whole tree dies.
Strict garden hygiene will help greatly. Never leave any dead wood lying about.
Soft fruit bushes with coral spot are best dug up and burned. More valuable trees and shrubs should be pruned to at least 4in below the affected area, and the wound painted over with a proprietary sealant that contains a fungicide.
Spray the remaining healthy parts with thiophanate-methyl at once, and spray twice more at three-weekly intervals. Encourage stronger growth in future by feeding, mulching and watering the plants.