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Blog

Host of the Month - Ash

Matt Parratt, Observatree Scientific Coordinator, looks at common ash, chalara ash dieback, and emerald ash borer

Matt Parratt  •  04 Dec 2023

Pests and diseases

Emerald Ash Borer

Native to Asia and Eastern Russia, the emerald ash borer is a threat to our already vulnerable ash trees.

Pests and diseases

Chalara Dieback of Ash

A chronic fungal disease believed to have originated in Asia, now widespread across Europe.

Blog

Ash Dieback in the National Trust

 Ash is one of our most important tree species both ecologically and culturally, and is generally considered to be the third most common tree in British woods, comprising around 12% of woodland tree cover. 

Luke Barley  •  23 Aug 2021

Blog

Host of the month - Ash

Matt Parratt highlights Common ash (Fraxinus excelsior), the well-known ash dieback disease and its associated pest, Emerald ash borer. 

Matt Parratt  •  14 Nov 2024

Blog

Chalara Dieback of Ash on my doorstep

Living in rural North Yorkshire, on the border with the East Riding, provides easy access to beautiful areas of the Wolds, Howardian Hills, Moors and coastal regions for country walks.

Charles Lane  •  01 Jul 2015

Blog

Emerald ash borer survey and detection: the Canadian experience

It's the International Year of Plant Health and our colleague from Canada give us details on their work with emerald ash borer. A highly destructive pest of ash trees.

Jon Sweeney, Erin Bullas-Appleton, Troy Kimoto & Ron Neville  •  22 Sep 2020

Pests and diseases

Mountain Ash Ringspot

First recorded in 1960, mountain ash ringspot is a virus that infects rowan trees and can lead to gradual dieback of the tree.

Blog

David Griffith, Tree Health Surveyor, goes above and beyond for tree health

David Griffith has been volunteering as a Tree Health Surveyor since 2014. Along with over 200 other volunteers involved in the project, David is tasked with surveying woods and trees for signs of pests and diseases including Chalara dieback of ash.

Helen Jones  •  24 Apr 2017

Video

Seasonal survey highlights - May to July 2024

In this video, Charles Lane, Plant Health Consultant at Fera Science Ltd, reminds us of the Observatree project resources that are relevant for the forthcoming season, focusing on the priority pest and diseases for May-July: Sirococcus tsugae, Elm zigzag sawfly, Chalara ash dieback and the Emerald ash borer.

00:14:07

Video

Host of the Month Ash - December 2023

Learn about Ash ID and it's associated pests and diseases.

00:40:41

Video

Pest and disease drop-in November 2021

Pest and disease drop-in session delivered to Observatree volunteers in November 2021. Presentations on volunteering activity (Ana Perez-Sierra), OPM monitoring (Andrew Hoppit), ash dieback in mature trees (Andy Gordon) and a new oak app (Rich Wright)

01:01:45

Blog

Help is at Hand - Benefits to an Observatree volunteer of buddying up with other organisations

A blog from our Lead Volunteer for Scotland, David Slawson. David talks about his experience working with Observatree associate organisation Scottish Natural Heritage.

David Slawson  •  13 May 2020

Blog

2016 Observatree mentoring events

During September and October, the Observatree project delivered eight mentoring events across Scotland, England and Wales for their network of tree health surveyor volunteers.

Helen Jones  •  22 Nov 2016

Blog

Observatree 2022 breaks all records!

Throughout the year, Observatree volunteers submitted 4899 tree health reports. Our best year to date. Not only that, volunteers also submitted the most pest and disease reports, they surveyed the most tree species in a single year and monitored the most sentinel trees.

Rebecca Gosling  •  21 Mar 2023

About us

Sue Quick

A

Blog

The role of citizen science in tree health in Slovenia

As part of the International Year of Plant Health, Observatree is hosting blogs from colleagues around the world who, like us, are working to slow the spread of invasive tree pests and diseases. This blog is from the Slovenian Forestry Institute who talk about their citizen science project LIFE ARTEMIS.

Simon Zidar and Dr Maarten de Groot  •  08 Apr 2020

Blog

Observatree Autumn Round Up

Following on from our last blog post where we shared what we’d been up to this summer, we thought we’d share what the volunteers have all been up to this summer!

Peter Crow  •  19 Nov 2019

Blog

Monitoring new pests and diseases on the horizon

Dr Charles Lane, plant pathologist and Observatree lead for Fera Science Ltd describes how potential new threats to our trees from other parts of the world are monitored and introduces Beech Leaf Disease.

Charles Lane  •  14 Nov 2020

Blog

Observatree at Ladybower Reservoir

Exploring the ancient woodlands of Ladybower Reservoir, with Midlands based Observatree volunteers.

Charles Lane  •  06 Jul 2023

Blog

Observatree raising awareness of tree pests and diseases in Wales

An update from our Lead Trainer, Suzy, about our stakeholder training days in Wales.

Suzanne Sancisi-Frey  •  10 Mar 2020

About us

Volunteers

Find out how volunteers support the Observatree project 

Blog

Coronavirus or Xylella: The importance of biosecurity, early detection and decisive action.

Professor Nicola Spence, DEFRA's Chief Plant Health Officer, explains why biosecurity is so important.

Professor Nicola Spence  •  16 Jun 2020

Blog

BGCI and the IPSN: Botanic gardens in the fight against invasive plant threats

Miles Kitching looks at how Botanic Gardens Conservation International (BGCI) and the International Plant Sentinel Network (IPSN) have been working together to tackle threats to plant biodiversity

Miles Kitching  •  31 Oct 2022

Blog

Observatree volunteers go from strength to strength

Over 13,500 reports have been submitted to date and our volunteers continue to build on this extremely valuable e-resource. During 2021, 174 reports were submitted to Forest Research for suspected priority pests and diseases.

Ana Perez-Sierra  •  21 Feb 2022

Pests and diseases

Phytophthora austrocedri

First found in the UK in 2011, Phytophthora austrocedri is a fungus-like plant pathogen that can infect and kill juniper.

Blog

2016 Training Observatree volunteers

 We held 12 training events, with venues in all volunteer regions in the UK including Scotland, Wales and Northern Ireland. 

Suzanne Sancisi-Frey  •  01 Apr 2016

Blog

The Observatree training roadshows 2019

Our annual training roadshow was a big success in 2019! Suzy talks about what happened on this year's training days.

Suzanne Sancisi-Frey  •  12 Nov 2019

Blog

A round-up of 2023

2023 in review and looking to the year ahead for Observatree.

Peter Crow  •  30 Jan 2024

Blog

Tree Health issues in Britain from the experts

Plant Health Week, in the International Year of Plant Health, provides an opportunity to reflect upon the current and potential future challenges facing Britain’s trees and what we can all do to help protect them.

Nicola Spence, Gerry Saddler & Martin Williams  •  08 Sep 2020

Blog

Host of the month - Lawson cypress

Matt Parratt, Observatree Scientific Coordinator, looks at Lawson cypress (Cupressus lawsoniana) and its associated pathogen, Phytophthora lateralis.

Matt Parratt  •  19 Jan 2024

Blog

The exceptional summer of 2022: extreme heat and drought and impacts on trees.

Matt Parratt, Observatree Scientific Coordinator, and colleagues at Forest Research, look at the effects of extreme heat and drought on trees.

Matt Parratt  •  18 Jul 2023

Blog

Citizen science and tree health in the UK

Our Lead Volunteer for the West Midlands, Andy Gordon, covers how citizen scientists have contributed to tree health in the UK.

Andy Gordon  •  13 Feb 2019

Blog

Observatree: Where it all began

Jane Barbrook, Plant Health & Seeds Inspectorate (Animal & Plant Health Agency), looks back at the start of the Observatree project and considers its ongoing success.

Jane Barbrook  •  05 Oct 2023

Pests and diseases

Agrilus fleischeri

Native to Asia, this beetle can infest poplar and willow trees with the beetles emerging from spring onwards.

Blog

Reflections on a February tree health conference

On two sunny spring days at Kew Gardens a conference with a rather sober topic took place: tree health early warning systems. 

Kate Lewthwaite  •  09 Mar 2016

Blog

Observatree Volunteers successes with Zoom

The first national lockdown in 2020 prevented the annual face to face training events for Observatree volunteers from taking place. As an alternative, a valuable series of technical webinars on pests and diseases, delivered by staff from across the Observatree partnership, were held instead. 

Richard Churchman & Paul Gill  •  02 Mar 2021

Blog

Host of the month - Birch

Matt Parratt, Observatree Scientific Coordinator, looks at birch (Betula species) and bronze birch borer.

Matt Parratt  •  26 Feb 2024

Blog

Volunteering to help our trees!

This Plant Health Week, Rebecca, our Observatree volunteer manager celebrates the achievements of our wonderful volunteers.

Rebecca Gosling  •  09 May 2022

Blog

Host of the month - Maple

This month Matt Parratt looks at Maples (Sapindaceae family), Asian longhorn beetle and Citrus longhorn beetle. 

Matt Parratt  •  19 Sep 2024

Pests and diseases

Phytophthora lateralis

Discovered in the UK in 2010, Phytophthora lateralis is a fungus-like plant pathogen that attacks the roots of Lawson cypress trees.

Blog

British cedars under attack?

Recently, cedars have been considered as an alternative forestry species, learn about how Sirococcus tsugae threatens this species.

Ana Perez-Sierra  •  16 Feb 2016

Blog

Host of the month - Maples

Matt Parratt, Observatree Scientific Coordinator, looks at Asian and Citrus longhorn beetles.

Matt Parratt  •  26 Sep 2023

Blog

Host of the month - Plane

Matt Parratt, Observatree Scientific Coordinator, highlights plane, plane lace bug and plane wilt.

Matt Parratt  •  29 Aug 2023

Blog

Host of the month - Plane

Matt Parratt highlights Plane trees (Platanus), Plane lace bugs and Plane wilt.

Matt Parratt  •  15 Aug 2024

Blog

Observatree Network Groups

Observatree is a national network of volunteers surveying tree health and acting as an early warning systems for tree health in the UK. A key way our volunteers and staff keep in contact is through the network groups in our forum.

Charles Lane  •  13 Jul 2020

Blog

Observatree is a Constant in 2020

We could say that this year has been unusual, and we had to adapt to new ways. However, nothing has stopped Observatree volunteers keeping their eyes open and reporting pests and diseases to the Tree Health Diagnostic and Advisory Service (THDAS). 

Ana Perez-Sierra  •  11 Feb 2021

Blog

2018 volunteer training days – a summary

We held 11 events across England, Wales, and Scotland from the end of May to the beginning of July.

Charlotte Armitage  •  15 Aug 2018

Blog

Welcoming new associates

One of the strengths of Observatree is the Partnership. We can draw upon the expertise and skills of different organisations in a collaborative effort to help protect our trees, woods and forests from a range of invasive pests and diseases.

Peter Crow  •  27 Jul 2021

Blog

A new collaboration as part of the UK Garden Sentinel Network

As Observatree continues to establish collaborative networks, we recently teamed up with the Botanic Gardens Conservation International (BGCI) and PlantNetwork to help raise awareness of tree health in wider audiences and promote surveillance and reporting by more people.

Peter Crow  •  26 Apr 2024

Blog

Emerging pests and diseases and their suitability for citizen science surveillance

A review of new and emerging pests and diseases.

Charles Lane  •  01 May 2024

Blog

Host of the month - Spruce

Matt Parratt, Observatree Scientific Coordinator, looks at common spruce (Picea species) and great spruce bark beetle.

Matt Parratt  •  01 Jan 2024

Blog

Host of the month - Spruce

For December, Matt Parratt looks at spruce (Picea species) and the Great spruce bark beetle.

Matt Parratt  •  19 Dec 2024

Blog

Host of the month - Oak

Matt Parratt, Observatree Scientific Coordinator, looks at oak (Quercus species) and acute oak decline (AOD).

Matt Parratt  •  04 Apr 2024

Blog

Protecting trees, woods and forests - we couldn’t have done it without you!

Peter Crow, Observatree’s project manager, concludes our 10 years of Observatree celebrations with a look at how citizen scientists help protect trees, woods and forests.

Peter Crow  •  05 Dec 2023

Video

Induction Two: Symptoms of Ill-Health and Site Surveys Recording [2023]

Induction Two introduces the signs and symptoms we look out for in Observatree, and introduces the general site survey method. Presented by Rebecca Gosling, Woodland Trust and Matt Parratt, Forest Research.

01:24:14

Blog

From Lens to Lab: The Power of Photography in Tree Disease Identification

David McKellar discusses the importance of photography in our diagnostic process and offers some guidelines for using our TreeAlert system to report suspected tree pests and diseases.

David McKellar  •  22 Aug 2024

Blog

2017 Training Observatree volunteers

Despite the best efforts of Storm Doris, Observatree year four volunteer training days ran smoothly over the course of February and March. 

Suzanne Sancisi-Frey  •  03 Apr 2017

Blog

10 highlights from the past 10 years of Observatree

Professor Nicola Spence, Chief Plant Health Office at Defra, reflects on 10 achievements and successes from the first 10 years of the ground-breaking Observatree initiative. 

Nicola Spence  •  01 Oct 2023

Blog

Pine Processionary Moth: Assessing the threat

PPM are spreading further north across Europe but are not established in the UK. We discuss the signs and symptoms to look out for.

Fritha West  •  31 Mar 2022

Blog

State of the World’s Plants

I had the pleasure of attending a ‘State of the World’s Plants’ symposium in May at Royal Botanic Gardens, Kew. 

Charles Lane  •  14 Aug 2017

Pests and diseases

Pests and diseases by tree species

To make it easier for you to spot tree pests and diseases, we have listed our 22 priorties by main host tree species.

Pests and diseases

Great Spruce Bark Beetle

Accidentally introduced to the UK in 1982, the great spruce bark beetle damages spruce trees by tunneling into their bark.

Pests and diseases

Elm Zigzag Sawfly

Elm zigzag sawfly larvae can defoliate whole elm trees leaving them vulnerable to further attack.

Pests and diseases

Red-necked Longhorn Beetle

The red-necked longhorn beetle larvae tunnel and feed under the bark of trees in the Prunus genus, such as cherries and plums.

Blog

On the trail of Sirococcus tsugae

Lead Volunteer, Andy Gordon, lets us know about his experience of surveying for Sirococcus tsugae.

Andy Gordon  •  14 Aug 2018

Pests and diseases

Beech Leaf Disease

Beech leaf disease is a newly described disease causing discolouration of beech leaves. 

Blog

Becoming an Observatree volunteer; learning together and becoming a part of the family.

Dr Kate Lewthwaite, Citizen Science Manager at the Woodland Trust, reflects on the role of the volunteer, the training opportunities and their vital to the Observatree project.

Dr Kate Lewthwaite  •  16 Oct 2023

Pests and diseases

Bronze Birch Borer

Native to North America, this wood boring bupestrid beetle is a serious pest to birch trees.

Blog

Defining Tree Health

Matt Parratt offers an explanation of how to define tree health in the context of Observatree. 

Matt Parratt  •  21 Nov 2024

Tree health

Report a tree pest or disease

Spotted a tree pest or disease? Report it as quickly as you can.

Blog

The science behind Observatree

As part of the ongoing ten-year celebrations, Peter Crow, Observatree's project manager, looks at the power of combining citizens and science.

Peter Crow  •  25 Oct 2023

Pests and diseases

Sweet Chestnut Blight

Sweet chestnut blight is a fungus that grows beneath the bark of sweet chestnut trees causing cankers that can girdle the tree.

Blog

Negative data is good!

One of the key messages we give Observatree volunteers is that you don’t have to find something to make a survey worthwhile or valuable.

Ellie Barham  •  08 Mar 2017

Blog

Beech Leaf Disease

A new disease of beech trees (Fagus spp.) named ‘Beech leaf disease’ (BLD) is spreading through forest areas in eastern USA and Canada. Charles Lane and Tom Prior discuss the threat posed to UK woods. 

Tom Prior  •  14 Jul 2022

Blog

Host of the month - Pine

Matt Parratt discusses the different types of Pine (Pinus) and Dothistroma needle blight (DNB). 

Matt Parratt  •  15 Jul 2024

Blog

It’s full steam ahead for Observatree in 2022

Observatree has now been in operation for eight years; and during that time, our volunteers have submitted over 13,500 reports.

Peter Crow  •  21 Feb 2022

Blog

Host of the month - Pine

Matt Parratt, Observatree Scientific Coordinator, highlights pines and Dothistroma needle blight.

Matt Parratt  •  29 Aug 2023

Blog

Host of the month - True Cedars

Matt Parratt, Observatree Scientific Coordinator, looks at true cedars (Cedrus species) and Sirococcus blight.

Matt Parratt  •  01 May 2024

Blog

Managing Sweet Chestnut Blight in the South West

Forestry Commission England’s Tree Health team plays an important role in the protection of England’s trees, woods and forests.

Emily Fensom  •  23 Jun 2017

Blog

‘Palmageddon’ heading our way

Anybody visiting tourist resorts in the Mediterranean today will likely encounter large numbers of dying and dead palms. What is the reason for this ‘palmageddon’ in the Mediterranean?  

Chris Malumphy  •  13 Apr 2018

Blog

Observatree adapts for Covid-19

As a project, the impact of Covid-19 in 2020 prevented the yearly hands-on Observatree training events for our volunteers and a switch to digital communications has helped tremendously.

Rebecca Gosling  •  27 Jul 2021

Pests and diseases

Acute oak decline

Affects mature oak trees across the UK. Thought to be caused by a bacterium causing oozing of dark fluid from cracks in the bark.

Blog

No sting in this tale

Find out about how Observatree volunteer, Amanda, made a big difference to the UK's oriental chestnut gall wasp outbreak response.  

Amanda Yorweth  •  23 Jul 2015

Blog

Oriental chestnut gall wasp – an update

What has happened with OCGW in the UK since it was first found in 2015?

Chris Malumphy  •  27 Jun 2018

Blog

Host of the Month - Sweet Chestnut

Matt Parratt, Observatree Scientific Coordinator, looks at sweet chestnut, Oriental chestnut gall wasp and sweet chestnut blight.

Matt Parratt  •  07 Nov 2023

Blog

Canker Stain of Plane

A summary of the damage caused by Canker Stain of Plane.

Alex Lewis  •  01 May 2024

Blog

The ups and downs of Dutch elm disease

Despite the fact that Dutch elm disease has been known and studied for almost 100 years, myths about this tree disease are not in short supply.

Joan Webber  •  21 Jul 2016

Blog

Observatree digital learning – the Director’s cut

Learning in the modern world is much more than just about your ABC’s.  You need to understand the potential opportunity with D’s and E’s.

Charles Lane  •  08 Nov 2017

Blog

Out with the old and in with the new: Welcome to Observatree

In 2017, Observatree produced more educational resources, ran successful media campaigns, trained stakeholders and volunteers across the county, attended events, held a volunteer celebration event and hosted a conference.

Peter Crow  •  07 Jan 2018

Blog

How does Observatree fit into tree disease?

Observatree project is asking citizens to help in protecting our trees from new pests and diseases, but why is this an issue and why is citizen science part of the answer?

Joan Webber  •  06 May 2015

Blog

Observatree attends the world’s first International Plant Health Conference

Colleagues from across the Observatree partnership, attended the world’s first International Plant Health Conference. Peter Crow, Observatree’s Project Manager, reflects on some of the conference’s key messages around the current and future global plant health challenges.

Peter Crow  •  17 Oct 2022

Video

Aerial Surveillance to Detect Pests and Diseases - February 2023

This talk will explain how the Forestry Commission use aerial surveillance (helicopters and drones) to survey trees for signs of poor health, disease and/or pest infestation. We will use Ips typographus as a case study to show how this work feeds into pest outbreak response work. We will also talk about the signs and symptoms looked for during drone surveillance for a range of emerging pests and diseases.

00:44:35

Blog

Host of the month - Elm

Matt Parratt reviews Elm (Ulmus species) and the Elm zigzag sawfly.

Matt Parratt  •  16 May 2024

FAQ

Observatree FAQs

Frequently asked questions about Observatree and tree health.

Blog

Host of the month - Sweet chestnut

Matt Parratt discusses Sweet chestnut (Castanea sativa) and its associated pest: the Oriental chestnut gall wasp, and its associated disease: Sweet chestnut blight.

Matt Parratt  •  17 Oct 2024

Blog

Host of the month - Beech

Matt Parratt looks at Beech (Fagus sylvatica) and its associated Beech leaf disease.

Matt Parratt  •  20 Jun 2024

Blog

The story so far: the difference we’ve made in five years

Ana Perez-Sierra, Head of Forest Research's Tree Health Diagnostic and Advisory Service, lets us know about the difference Observatree has made.

Ana Perez-Sierra  •  11 Dec 2018

Blog

Simulating a longhorn beetle outbreak

Find out about the creation of the longhorn beetle outbreak training trees, based at the Yorkshire Arboretum.

Ellie Barham  •  14 Feb 2017

Blog

New look for TreeAlert!

Lucy Turner, TreeAlert Coordinator, gives an overview of some of the latest improvements to the TreeAlert system.

Lucy Turner  •  18 Jul 2023

Blog

Observatree II: Thoughts from Nicola Spence, Chief Plant Health Officer, Defra

Welcome to Observatree II! Read thoughts from DEFRA's Chief Plant Health Officer, Nicola Spence, as the project moves forwards.

Professor Nicola Spence  •  25 Oct 2018

Blog

A record-breaking 2019 and new developments for 2020

2019 was a record-breaking year for the project, with almost 4400 tree health reports submitted by our volunteers.

Peter Crow  •  20 Jan 2020

Blog

Globose scale, a southern European pest of plum and peach, heading our way

Chris Malumphy from Fera Science Ltd provides us with an overview of globose scale and what threat it poses to UK trees.

Chris Malumphy  •  06 Sep 2016

Blog

Tree health early warning in the UK: a celebration of Observatree

A dark November evening in London was brightened as many of those involved in the Observatree project gathered at the Houses of Parliament for a reception to celebrate what the project has achieved over the first three years and to help look towards its future.

Peter Crow  •  22 Nov 2016