Honey fungus

What you see

A woody plant declines or dies suddenly, often one branch at a time. Peel the bark at the base and you find a sheet of white fungal tissue smelling strongly of mushrooms. Black bootlace-like strands run through the soil, and honey-coloured toadstools appear in clumps at the base in autumn.

Conditions

Spreads through soil by those bootlace strands from an infected stump or root, sometimes many metres. Stressed and waterlogged plants succumb first, healthy ones can resist for years.

Treatment

There is no chemical control available. Dig out infected stumps and as much root as possible - leaving a stump is leaving the food source. A physical barrier of heavy butyl liner buried 45 cm deep can stop the strands.

Prevention

Remove old stumps rather than leaving them. Keep valuable trees unstressed and well watered. Replant with more resistant species such as bamboo, box, yew, holly or hawthorn.

Months: September, October, November

Plants

Apple, Plum, Cherry, Rose, Hydrangea, Privet, Wisteria, Peach

Remedies

Not recorded — the field is blank rather than guessed.

The thing people get wrong

The white sheet under the bark with the mushroom smell is the only certain identification - the toadstools are seasonal and the bootlaces can belong to harmless relatives. And it is worth being clear that nothing you can buy will treat this. What actually decides whether it spreads is dead wood: every old stump left in the ground is a fuel depot from which it advances.