Coral spot

Nectria cinnabarina

Orange-pink pustules on dead or weakened wood that can spread into live branches. Prune out affected wood to a clean cut, leaving no snags or stubs.

Fungus Serious Airborne sporesRain splashSpread on tools & hands Spreads to neighbors

What you'll see

Clusters of coral-pink to orange pustules, each about the size of a pinhead, studding dead bark.
They appear first on snags, stubs, prunings left in the border and old pea sticks, then move onto living stems.
A branch above the affected area wilts suddenly in summer with the leaves still attached.
Dark red-brown fruiting bodies replace the pink ones on wood that has been dead longer.
Bark at the boundary is sunken and dead, with a clear edge against healthy tissue.

Why it happens

A weak parasite that lives on dead wood and can move into living branches through wounds and stressed tissue. Spores are produced in huge numbers from the pink pustules and are splashed and blown onto pruning cuts. It is essentially a hygiene disease: it is fed by dead wood left lying about or left standing as stubs.

Damp weather and plants under stress — drought, waterlogging, poor planting, hard pruning at the wrong time — allow it in. A garden with old prunings in the beds and dead stubs on shrubs has a constant spore source.

Treating it

Prune out all affected wood well below the last pustule, into clean, unstained tissue.
Cut back to a bud, a junction or the branch collar — never leave a stub for it to colonize.
Burn or bin the prunings at once; they will keep producing spores where they lie.
Sterilize tools between cuts, and prune in dry weather.
Improve the plant’s vigor with mulch, water and sensible feeding so it can resist further entry.

Keeping it away

Clear dead wood, prunings and old bean poles out of the beds rather than leaving them in situ.
Always cut to a collar or a bud, and keep secateurs and saws sharp so cuts are clean.
Prune susceptible shrubs — maples, magnolias, elaeagnus, currants — in dry weather at the right season.
Keep plants unstressed with mulch and water; coral spot rarely troubles a vigorous specimen.
Remove dying branches promptly rather than waiting to see whether they recover.

Who gets it

Maples, magnolias, elaeagnus, figs, currants, gooseberries and many woody shrubs, especially where dead wood is left standing.