Dealing with ash dieback at Sizergh

Picture showing a felled tree with a hollowed out, blackened trunk, caused by the disease

If you’ve visited Sizergh recently, you may have spotted some tree felling on the driveway and around the wider estate. A survey conducted by our rangers last summer discovered that a large percentage of trees were badly infected with ash dieback, an incurable disease which threatens an estimated 80 million ash trees in the UK.

What is ash dieback?

Ash dieback is caused by a fungus called Hymenoscyphus fraxineus. Originating in Asia, it is believed the fungus spread because of the movement of plants as part of global trade. As its spores are airborne, the fungus spreads quickly and is impossible to control. Over a third of the trees in the UK are ash trees and they shape some of our best loved landscapes. It is predicted that over 90% of these will eventually be lost to the disease, having a devastating impact on the British landscape, homes for wildlife and biodiversity.

Can it be treated?

There is currently no cure or treatment for ash dieback, although a small percentage of ash trees do develop natural immunity.

Why are so many trees being cut down all at once?

Unfortunately, the extremely dry conditions in spring last year (2020) resulted in the rapid deterioration of infected trees. They now pose a risk to public safety and are in urgent need of felling. The national lockdown also meant the maintenance work and felling our rangers would normally be carrying out at that time was put on hold.

How many trees will be cut down?

The infected trees will only be removed where they pose a risk to visitors and to the public. Over the entire course of felling (which began in 2017), we estimate Sizergh will have lost around 2000 ash trees. This sounds like a big number but it’s worth remembering that the estate includes over 30 different woodlands and covers 1600 acres.

Will my visit be affected?

No – although there may be times when certain footpaths need to close temporarily when felling is taking place nearby, and it may be noisy during these periods.

Will you plant new trees?

We will be assessing each woodland in turn to carefully consider the best tree species for each location. Nature conservation will be our priority, along with choosing native tree species which are resilient to disease. 

How will you protect any remaining ash trees?

Certain types of weather enable the spores to spread more easily – so the warm wet autumn last year also worsened the outbreak. By working together with the Forestry Commission and neighbouring woodland owners we can fell infected trees quickly and help to limit the spread of the disease. As mentioned earlier, replanting will be done with species which aren’t susceptible to ash dieback.

What can I do to help?

Unfortunately this isn’t just a problem at Sizergh; across the country, the National Trust is expecting to remove 40,000 trees this year at a cost of more than £2 million. Between 75 and 95 per cent of all ash trees will be lost in the next 20–30 years and our aim is to restore woodlands for future generations to enjoy. If you’d like to help the cause we would be grateful for any donations towards our Everyone needs nature appeal. Thank you.

A chaffinch in summer plumage

Everyone needs nature appeal 

Trees that give us life, calming coastlines to walk along and bees that hum among the flowers. Imagine if this all disappeared in the blink of an eye. You can give nature hope when you donate today to help look after these natural spaces.