Destructive Disease Now Found on Larch in South East England

The forestry industry was dealt a blow with news that Phytophthora ramorum (P. ramorum) has been found on larch trees in South East England for the first time.

P. ramorum has been confirmed in larch trees in two woodlands: one in West Sussex, and the other in Surrey. The Forestry Commission first became concerned when larch trees showing symptoms were spotted during a helicopter survey of the region in June, and ground-based checks confirmed the surveyors’ suspicions.

Ramorum disease has been responsible for the premature felling of more than 3 million larch trees in the United Kingdom since it was first found killing larches in the West Country in 2009. Most cases have occurred in the wetter, western parts of Great Britain as well as Northern Ireland, the Republic of Ireland and the Isle of Man. This month’s confirmation that the disease has reached South East England is the first time it has been recorded so far east, although the organism has previously been found in the region infecting other plants, such as rhododendron.

Alison Field, South East England Director for the Forestry Commission, explained,

“Like all phytophthora organisms, P. ramorum thrives in the kind of wet weather we have had this year. It is also significant that both of the affected woodlands are close to areas where rhododendron shrubs have been infected with P. ramorum as well, so although this is bitterly disappointing news, it is understandable that it has spread into local larch trees.

“Sadly, the only treatment to prevent this disease from killing millions more larch trees is to fell the infected trees as quickly as possible, before they can produce the spores that can be spread by wind and mist to infect more trees.”

The Forestry Commission has issued statutory “plant health notices” to the affected owners, requiring them to fell the infected larch trees and others nearby, and Ms Field added,

“We are very grateful for the rapid response of the woodland owners affected to fell their trees as quickly as possible to remove the threat to other woods and woodland owners in the area.

“I would urge all woodland owners in the South East to inspect their trees regularly for signs of ill health, and to report anything suspicious. Those who have rhododendron plants in their woods or gardens should keep a close eye on them too, because infected rhododendron can also produce millions of the spores which spread the disease.”

The Commission’s aerial surveillance team was flying over South East England again this week to check for any further signs of diseased trees.

Further information about P. ramorum, including guidance to recognising the symptoms, is available on the Forestry Commission website.

Suspected cases in England can be reported to plant_health_england@forestry.gsi.gov.uk or by telephone to 0117 372 1070.

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