If you suspect you have found a tree pest or disease anywhere in England, Scotland or Wales, please report it to us immediately using TreeAlert.  Your report will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, please report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

By using these on-line tools, you are helping us to gather information about the health of the nation’s trees, woodlands and forests by reporting signs of  potentially dangerous (and sometimes “new”) tree pests and diseases. The information you provide will be shared with other organisations responsible for plant health across Britain to prevent the spread of pests and diseases.

If you have problems with TreeAlert, and are sure this is not the result of a poor internet connection, please contact us so that we can help you resolve the issue.

If you suspect a possible tree disease anywhere in England, Scotland or Wales, please report it to us via TreeAlert where you will be required to upload photos. Your reports will be assessed by our scientists and if necessary, forwarded to the plant health authorities for appropriate action.

In Northern Ireland, please report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

Images are important in the diagnosis of tree health issues. If you are sure this is not the result of a poor internet connection, please check that your image size is not too large and try renaming the image file before re-uploading.  If you are still having problems please use the contact form.

Please visit the TreeAlert section where you can login with your username and password. Once logged in, you can update your email address.

There are lots of factors that will determine whether insects or bugs are dangerous to your trees. The best course of action is to submit a report using TreeAlert.

Pesticide legislation is complex and only a few are approved for use on trees. Such use is invariably for very specific purposes under prescribed conditions. Useful, authoritative, and up-to-date information on the use of pesticides in the UK can be found on the HSE website.

If you suspect you have found an OPM nest or caterpillars anywhere in England, Scotland or Wales, please report it to us immediately via the OPM reporting line on TreeAlert. Your reports will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

You will need to upload a clear, well-lit photograph to TreeAlert or TreeCheck, but do not risk contact with the hairs when taking this.

Before reporting a suspected sighting, please check the ‘Identification’ section and the pictures in our OPM Manual to ensure that: the affected tree is an oak tree (most oak species are fairly easy to identify by their distinctive leaves and bark); and the caterpillars are oak processionary moth caterpillars and not those of another species.

Please report sightings of nests even if you do not see any caterpillars, because nests are a useful sign that the pest is in the area.  Do not touch ‘spent’ nests, which can contain large numbers of the irritating hairs.

If you suspect you have found an OPM nest or caterpillars anywhere in England, Scotland or Wales, please report it to us immediately via TreeAlert. Your reports will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

You will need to upload a clear, well-lit photograph to TreeAlert or TreeCheck, but do not risk contact with the hairs when taking this.

Before reporting a suspected sighting, please check the ‘Identification’ section and the pictures in our OPM Manual to ensure that: the affected tree is an oak tree (most oak species are fairly easy to identify by their distinctive leaves and bark); and the caterpillars are oak processionary moth caterpillars and not those of another species.

Please report sightings of nests even if you do not see any caterpillars, because nests are a useful sign that the pest is in the area.  Do not touch ‘spent’ nests, which can contain large numbers of the irritating hairs.

There are a number of species of moths and butterflies that have hairy caterpillars.

Before reporting a suspected sighting through TreeAlert, please check the ‘Identification’ section and the pictures in our OPM Manual to ensure that: the affected tree is an oak tree (most oak species are fairly easy to identify by their distinctive leaves and bark); and the caterpillars are oak processionary moth caterpillars and not those of another species.

If you suspect you have found a pest or disease anywhere in England, Scotland or Wales, please report it to us immediately via TreeAlert. Your reports will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, please report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

If you suspect you have found Xylella fastidiosa anywhere in England, Scotland or Wales, please report it to us immediately via TreeAlert. Your reports will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

If you suspect you have found Chestnut Blight anywhere in England, Scotland or Wales, please report it to us immediately via TreeAlert. Your reports will be assessed by our scientists and forwarded to the plant health authorities for appropriate action.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

Plot marker posts and / or trees which have markings or numbers painted on them are used to mark the boundaries of experiment plots and different treatments within them so they can be remeasured. Remeasurement is often many years (sometimes decades) later due to the long life-span of trees.

There are lots of factors that can affect the health of trees, and that can cause browning of foliage and/or dieback.  Some factors are biological (such as insects, fungi and bacteria) and others are abiotic (such as drought or frost). The best course of action is to submit a report using TreeAlert so that we can try to assist you.

We are unfortunately unable to deal with local area tree issues. If the tree is your responsibility you should consult with a qualified arboriculturalist or tree surgeon to ensure that the tree is safe. 

Unfortunately we cannot deal with local area tree issues. If a hedge or tree is causing a nuisance or you think it is not being properly maintained, you should contact the landowner first and ask them to cut it back. They may not be aware it is causing a problem. If you don’t know who is responsible for a tree or hedge on the edge of your property you should check your property deeds and speak with your neighbours. For council owned trees, or where you are unsure who owns them, you should contact the relevant team within your local council.

If you are concerned about the safety of a tree, you should contact the landowner to make them aware of your concerns. They may not be aware it is causing a problem. If you don’t know who is responsible for a tree on the edge of your property you should check your property deeds and speak with your neighbours. For council owned trees, or where you are unsure who owns them, you should contact the relevant team within your local council.

If the tree is on your property you can contact the Arboricultural Association and search for a qualified arborist in your area.

Three simple checks you can make to see if your tree is dead:

1. Check to see if the stems of the tree are flexible, if they snap easily it would suggest the wood is dead.
2. Scratch a limb or a branch with a sharp knife and if it’s green underneath it is alive, if its brown it would suggest the wood is dead.
3. Check to see if the buds are plump.

The best course of action is to submit a report using TreeAlert. Your report will be assessed by our scientists who will be able to provide advice.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

We are unfortunately unable to deal with local area tree issues.

If the trees are your responsibility you should consult with a qualified tree professional or your local woodland officer.

If you are concerned about trees owned by somebody else, you should contact the landowner to make them aware of your concerns. They may not be aware of the issue that you have noted.

In either case, you can also submit a report using TreeAlert. Your report will be assessed by our scientists and in some cases the local Woodland Officer will be notified and will be able to provide advice.

You can report a longhorn beetle anywhere in England, Scotland or Wales, via TreeAlert. Your reports will be assessed by our scientists and if necessary, forwarded to the plant health authorities for appropriate action.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

You will need to upload clear, well-lit photographs to TreeAlert or TreeCheck for our scientists to be able to identify the type of longhorn beetle.

You can do this via the General Report on TreeAlert where during the reporting process you will be asked if you are reporting a pest on a tree or not. This can include a pest, e.g. a caterpillar or beetle on your garden furniture, house wall, pavement etc.

Firstly please check the distribution map and if you think you have spotted ash die back in a new previously unreported area in England, Scotland or Wales, please report it to us via TreeAlert.

Please see the Chalara dieback of ash symptoms guide to help identify it.

In Northern Ireland, please report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.

The best course of action is to submit a report using TreeAlert. Your report will be assessed by our scientists who will provide advice on managing the disease, however treatment is not always possible.

In Northern Ireland, report suspected sightings with TreeCheck, the all-Ireland pest reporting tool.