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Ash to be stripped naked by Deirdre?

Conservation charity the Woodland Trust warns that autumn colour could come to an abrupt end with the arrival of the next major storm - Deirdre.

The Trust’s Nature’s Calendar project – which asks the public to record seasonal events– has only received 176 records of bare trees so far, with the earliest being on 2 October.1 This time last year, the Trust had received 181 records of bare trees (the earliest being an elder on 28 September), and the baseline average date2 for this event is 15 November. So - at the moment - 2018 is not unusual.

However, weather conditions such as high winds and storms could quickly change this.

Bare beech tree (Photo: Ben Lee/WTML)
Bare beech tree (Photo: Ben Lee/WTML)

A tree going bare is an important event to take note of as it signals the end of a deciduous tree’s growing season. Trees like these shed leaves as a strategy to avoid harsh winter weather. Reduced temperatures and light levels prompt trees to re-absorb nutrients from the leaves, and then hormonal changes in the leaf weaken the connection between the stalk and twigs.  Normally a strong gust of wind is required to finish the process, so it’s hard to know when exactly it will happen.

The next major storm to hit the UK will be named Deirdre but as of yet it is unclear when - or if - this will strike. With this uncertainty in mind, the Woodland Trust wants more members of the public to sign up to Nature’s Calendar and be ready to take note when they spot naked boughs for the first time.

Martha Boalch, citizen science officer for the Woodland Trust, said:

“When trees go bare varies as it is so dependent on the weather. However, during the storm season we could expect a sudden rush of leaves falling to the ground. That’s why we are calling for more people to sign up to Nature’s Calendar; we want to learn when this happens, and which storm could be held responsible.

“Though we might expect seasonal activity to quieten down, spring also starts appearing earlier and earlier, so now is the time to look out for unusual activity – in the past we’ve had frog spawn in November and snowdrops in December!”

The weather has already wreaked havoc with the seasons this year – an early spring was paused by the Beast from the East, the summer heatwave caused berries to ripen early, and conkers suffered due to drought. Temperature research by the Met Office suggests that the growing season is extending by up to a month3, and this is corroborated by Nature’s Calendar data; budburst is happening earlier and leaf fall later. Future climate change scenarios also predict more stormy weather for the UK.

Anyone can record the changing seasons with Nature’s Calendar. To get involved or find out more, go to:

- Ends –

Notes to editors

For further information contact the Woodland Trust press office on 01476 581121 or email

The Woodland Trust is the largest woodland conservation charity in the UK. It has over 500,000 supporters. It wants to see a UK rich in native woods and trees for people and wildlife.

The Trust has three key aims:  i) protect ancient woodland which is rare, unique and irreplaceable, ii) restoration of damaged ancient woodland, bringing precious pieces of our natural history back to life, iii) plant native trees and woods with the aim of creating resilient landscapes for people and wildlife.

Established in 1972, the Woodland Trust now has over 1,000 sites in its care covering over 22,500 hectares. Access to its woods is free.

  1. Statistics so far, as noted by Nature’s Calendar recorders can be found in an excel spreadsheet here.
  2. Baseline averages: Average date for trees going bare is 15 Nov, based on data from 2007. 2007 is the year used for baseline averages because it had autumn temperatures very similar to the 30 year average (1961-1990).

The 2017 and 2018 records were taken up until 19 November:

  • 2018: How many bare trees we have recorded so far – 176 bare trees recorded so far, the first being a (potentially diseased) horse chestnut in Kent.
  • 2017: This time last year Nature’s Calendar had received 181 records. Earliest was an elder on 28 Sept 2017. The average date for trees going bare in 2017 was 13 November.
  1. Please see press release from the Met Office in 2016 here.

For images, twig ID and full stats go here. For time lapse footage of trees throughout the seasons go here.