Gardeners told to burn fallen ash leaves

 Gardeners should burn fallen leaves from ash trees to help control the spread of the deadly dieback fungus, the Government has said.

 The advice was issued amid growing fears that composting leaves from infected ash trees could allow the disease to spread. It has already been confirmed at 135 sites across Britain.

Experts fear that spores from the Chalara fraxinea fungus may survive in compost. Some local authorities have told householders not to put fallen leaves and twigs into compost bins, while officials have warned against transporting leaves and compost over long distances.

Scientists are investigating whether the Chalara fungus can survive in compost or whether the heat produced as material rots is enough to kill the disease.

أ¢â‚¬إ“It is an area we are looking into urgently,أ¢â‚¬آ‌ said Martin Ward, head of policy at the Food and Environment Research Agency (FERA).

أ¢â‚¬إ“Leaf litter does not compost at high temperatures but commercial sites may get hot enough to kill off the fungus.

أ¢â‚¬إ“However, anything that moves leaves over a long distance and especially to other areas that are disease-free should be discouraged.أ¢â‚¬آ‌

Researchers studying the fungus have warned that it could survive for at least a year in compost.

Tadeusz Kowalski, a mycologist at the University of Agriculture in Krakow, who is the worldأ¢â‚¬â„¢s leading expert on the fungus, said his research had shown that it was able to survive for long periods and could resist competition from other organisms.

أ¢â‚¬إ“It is likely that the fungus can survive at least one year in compost and after its distribution it can develop fruitbodies,أ¢â‚¬آ‌ he said.

The official advice issued by the Department for Environment, Food and Rural Affairs was to burn leaves from ash trees on site.

أ¢â‚¬إ“Moving ash leaves for purposes other than destruction, such as mulching or use on allotments, should be avoided,أ¢â‚¬آ‌ it said.

The Association for Organics Recycling has told local councils not to collect ash tree leaves for composting in infected areas, but some authorities have advised householders to put fallen ash leaves into bins with their household waste so it can be buried in landfill.

Guy Barter, the head of the Royal Horticultural Society advisory service, said the conflicting advice was confusing for gardeners. أ¢â‚¬إ“There could be a lot of neighbourly disputes if one person gathers up all the leaves to burn them and his neighbour lets them remain on the ground,أ¢â‚¬آ‌ he said.

أ¢â‚¬إ“There is huge concern about this, but the calls we are getting suggest that people are very confused about what they are looking for and what to do.أ¢â‚¬آ‌

Chalara fraxinea has now been confirmed in 15 nurseries, 55 recently planted sites that were supplied by these nurseries and 65 sites where it has infected mature trees.

About 100,000 young trees have been burned after being found to be infected. The government has said it will not destroy any mature trees affected.

At Farnley Estates Nursery at Farnley Tyas, near Huddersfield, West Yorks, 1,700 infected saplings were burned, while at Bernhard Nurseries in Rugby, Warks, 500 one-year-old trees were destroyed.

Crowders Nurseries in Lincolnshire destroyed 50,000 ornamental and native ash trees, while Plants Ltd at Chobham, Surrey, had to burn a batch of 100 seedlings. The fungus has also been found at Christies in Fochabers, Moray.

Among the woodlands to be affected are one in Guisborough, Teesside, another at Arger Fen Nature Reserve in Assington, Suffolk, and a small, privately-owned woodland in Carmarthenshire.

Ash trees in Dalbeatie Forest in Dumfries and Galloway are also among those to have tested positive.

Experts believe that the fungus has been circulating in mature woodland in Britain for at least two years after blowing over the Channel from infected woodland in northern France.

Meteorological modelling revealed a number of days in the past few years when this might have happened. Scientists believe it was the cool, wet weather this summer that allowed the fungus to begin inflicting widespread damage on Britainأ¢â‚¬â„¢s woodland.

Research from Poland, where the disease was first identified, has shown that some strains of the fungus flourish in cooler summer conditions, when they produce spores.

Prof Ian Boyd, the chief scientific adviser for Defra, said there was now little chance of stopping the spread of the disease and that ultimately it would lead to some permanent changes to the structure of Britainأ¢â‚¬â„¢s forests.

The Forestry Commission has been conducting research on which trees may be able to replace the ash, which makes up a third of the nationأ¢â‚¬â„¢s woodland.

They believe that planting birch, lime, walnut and chestnut could provide alternatives while still maintaining the open and airy shelter provided by ash forests. They have also suggested using sycamore as an alternative to the valued light-coloured ash timber.

Prof Boyd said: أ¢â‚¬إ“What we will see is a decline in the ash tree over many, many years.

أ¢â‚¬إ“We have got to see that as an opportunity to change the structure of our forests to introduce new species and different forest structures to replace those ash trees that are in decline. There are many good hardwood trees that will look very similar to ash trees.أ¢â‚¬آ‌

Foresters are already beginning to plan for a future without ash. The Jubilee Woods Project, which this year aimed to plant three million trees to mark the Queenأ¢â‚¬â„¢s Diamond Jubilee, will not use ash.

The Woodland Trust, which organised the project, had planned for ash to make up 20 per cent of the Jubilee woodland, but will now use species such as oak and birch.

The Chalara crisis has devastated the forestry industry. Many growers and nurseries yet to be affected by the disease face having to destroy millions of trees that they cannot sell or transport due to the ban on movement.

Jamie Dewhurst, from J&A Growers in Warwickshire, said: أ¢â‚¬إ“I have half a million ash sitting in the field that no one wants to plant. None of them are infected but I am going to have to destroy them all.أ¢â‚¬آ‌

There is no compensation scheme for those who have to destroy trees or lose them to the disease.

Robert Crowder, the chairman of Crowderأ¢â‚¬â„¢s Nurseries, is considering suing the government for أ‚آ£200,000 of losses after he had to destroy 50,000 of his trees.

He believes that alleged delays in inspecting the trees and a failure by plant inspectors to take biosecurity measures contributed to the spread of the fungus within his crop.

أ¢â‚¬إ“Initially, only 15 trees were found to be infected, but the plant health inspectors from FERA came down and were moving around without taking appropriate biosecurity measures,أ¢â‚¬آ‌ he claimed.

أ¢â‚¬إ“They had no white suits and did not wash their feet. They could have easily carried the disease from tree to tree.أ¢â‚¬آ‌

FERA officials insisted that appropriate precautions had been taken.

MPs will debate the Governmentأ¢â‚¬â„¢s response to Chalara for the first time tomorrow.

Mary Creagh, Labourأ¢â‚¬â„¢s shadow environment secretary, criticised the government for cutting nearly 38 posts in the Forestry Commissionأ¢â‚¬â„¢s forest research section that investigates tree diseases. The commissionأ¢â‚¬â„¢s budget has also been cut.

A spokesman for Defra said: "Plant health inspectors visited Crowders a number of times between June and September and kept the owners updated on action being taken. During that time the owners could have taken the decision to destroy that stock for themselves.أ¢â‚¬آ‌

He added: أ¢â‚¬إ“At a time when our trees face increasing threat from a range of diseases, and in a tight financial climate, we believe that resources are best spent on surveillance and trying to tackle the disease.أ¢â‚¬آ‌