Editorial: A dire threat to Britain's ash trees

Once, Britain was a country of elm trees. Then Dutch elm disease arrived, in the late 1960s, and within three decades nearly all of them were wiped out. Now, a similar fate threatens another glory of the British woodland: the ash.

Chalara fraxinea – known colloquially as ash dieback – is here and it is spreading. Last week, the infection was found at two sites in East Anglia; the tally jumped to 20 at the weekend. With some 80 million ash trees making up nearly a third of our woods and hedgerows, the impact of the disease could be devastating.

In an effort to grip the problem, the Government will today ban the import of ash trees. But why the delay? Ash dieback has ravaged European woodlands for more than a decade and the first cases turned up in Britain nearly nine months ago, albeit in nursery stocks rather than in the wild.

The Environment Secretary points out that 50,000 saplings have already been burned. He also claims that it is only now, as the planting season begins, that an import ban has any meaning. For all Owen Paterson's efforts, the Government's response is still inexcusably tardy. Northern Ireland – sensibly – restricted imports in February, as soon as the first cases were found. By waiting until the infection has appeared, the Government has left itself fighting a rearguard action.

Efforts to control the spread of the disease must be more fleet-footed. A public information campaign to identify infected trees would help. As would more research into the fungus. It would be useful to know if trees are contagious before they exhibit symptoms, for example, and whether it is possible that spores spread from the Continent on the wind, as Mr Paterson now suggests.

Action must also be taken to prevent a repeat of the situation. The Woodland Trust's proposal for a tree passport scheme merits consideration. Ash dieback will not be the last imported disease to endanger the British countryside. We need to get better at keeping them out.