THE CANDLES on the horse chestnut trees are just beginning to fade as I write this, having looked remarkably healthy despite our on-off, hot-cold-wet spring. When I was a lad, such a show of the brilliant white cones of blossom (sometimes a salmon pink on speciality trees) would have been observed with delight because it meant a good show of conkers in three or four months times.

Whether or not modern children play conkers is a matter of dispute, what with the rival attractions of computer games and bans imposed by the jobsworths of the ‘elf ‘n safety tyranny (poor little Johnnie might get hit on the thumb) is a matter of conjecture.

What, however, is a matter of the gravest concern to any country lover is that the conker tree itself may not survive if the latest pessimistic forecasts are to be believed. For the horse chestnut, beloved of Constable and other landscape painters as well as conker playing kiddies, could well be on the way of the once elegant elm. And if that is not bad enough, the clouds of doom also hang over the oak, very symbol of old England, and the ash too.

The horse chestnut is under attack from no fewer than three different assailants, according scientists at Aberdeen University. They include a moth which causes their leaves to drop in mid-summer, bacteria which makes their branches follow suit, and a fungus which kills their bark.

“The best thing to do would be to cut them all down now,” says tree expert Prof. Steve Woodward, because the triple killers are already taking hold in the south of England and all the estimated 500,000 horse chestnuts in the UK could be gone in two decades.

As it that weren’t bad enough, the Forestry Commission is pretty gloomy about the long-term prospects of the oak, which is suffering from acute oak decline (AOD) caused by as yet unidentified bacteria which can kill this mighty tree in within five years. AOD is a condition known to be affecting several thousand oak trees, mostly across East Anglia, the Midlands and South East England.

And then there is Chalara infection of ash, also known as ash dieback, caused by a fungus known as Chalara fraxinea. The disease causes leaf loss and crown dieback and is usually fatal. The most pessimistic prognosis is that this will kill every ash tree in the land within a few decades.

Here in the Yorkshire Dales, we have both an advantage and a disadvantage when it comes to fighting tree diseases. The good bit is that disease tends to travel very slowly and, so far, most of them are largely confined to coastal areas in the south and east of the country. That, hopefully, will give the scientists time to find cures before they arrive here en masse.

However, the other side of this very nasty coin is that we already have one of the thinnest tree coverage rates of any part of the UK, with perhaps the exception of the Scottish Highlands. The reason for this in both cases was the large-scale clearance of forests in the 18th and 19th centuries to make way for sheep pasture (although, thankfully, we never suffered anything like the horrors of the Highland Clearances).

This means that should the killers arrive, we have fewer potential victims but the loss of any of those would have a much more serious impact than in more heavily wooded areas of the nation. Such is the concern that the Yorkshire Dales National Park Authority (NPA) has published on its website a guide to walkers advising them how to prevent unintentionally helping to spread disease.

The NPA and the Yorkshire Dales Millennium Trust, one of the most successful bodies created at the beginning of the century to promote environmental and social projects, both have tree planting programmes involving hundreds of thousands of saplings which will take a decade or more to come to anything near fully grown – and fingers are being crossed by forestry professionals that they will become established, strong and healthy, before any of the tree killers travel this far north.

But the most worrying aspect of this situation, which I have reported on many times in the past decade, is the way these diseases enter the UK. It is possible, I suppose, that the tiny moths that attack the mighty oak can be blown across the Channel or the North Sea. The same, conceivably, could apply to the spores of the fungi that are attacking several species.

But the most likely cause of this (literally) budding disaster is that they come in on plants and saplings imported from the Continent, either by timber merchants or garden centres. Now at a time when Britain cannot protect its borders from thousands of illegal immigrants, we ca hardly expect our customs people to do a (sorry again) root and branch inspection of every import of living plants.

But the European Union has untold thousands of civil servants working on red-tape schemes to hinder British business. Could they not be put to use bringing in a licensing system to make plants exporters inspect and if necessary sterilise their stock? This is the first, and probably the only time, I have pleaded for more EU regulation. But if it saves our woodlands, something has to be done – and soon!

*Gardeners, farmers and landowners worried about the spread of tree diseases can get advice of how to spot the early symptoms by going to the Forestry Commission website www.forestry.gov.uk/