2. Report a dangerous tree

The following form as distinct from the routine service request form, is for the reporting of trees believed to be imminently dangerous. Please read the following guidance before deciding whether your message is a service request or whether you are reporting an imminently dangerous tree.

Commonly expressed concerns and general advice

The tree is too tall, too big, it has a broad crown:
A tall tree and/or a broad spreading crown does not, of itself, make it a dangerous tree. Trees will grow depending on their type and on the presence of external influences such as adjacent structures, natural competition from other trees, soil type and fertility or microclimate.

The tree sways when it is windy:
A tree swaying in the wind does not, of itself, make it a dangerous tree. Trees will naturally bend and sway in the wind, as the pliability in the branches is a natural mechanism that helps prevent fracture.

The tree has a lean:
A tree that has grown with a lean does not, of itself, make it a dangerous tree. The tree develops fatter growth rings on one side to make it stable. There is likely be a problem, however, if a previously vertical tree suddenly develops a lean.

The tree is hollow:
Some hollow trees may have so little healthy tissue surrounding the hollow area that they must be regarded as dangerous, but this is by no means the norm. Trees do not become hollow overnight - it can take decades - and while the centre of the tree (the heartwood) may be decaying, the tree continues to lay down healthy wood (sapwood) around the outside of its trunk. This results in the formation of a cylinder, the strength of which depends upon the percentage of healthy to unhealthy tissue. Inspection by an expert is recommended.

How does a dangerous tree differ from a defective tree?

Most trees have defects, but the vast majority do not render a tree dangerous. Defects may include minor dead wood where squirrels have stripped bark or minor decay pockets where bark has been damaged and the tree has suffered bacterial or fungal infection. It is the type and extent of the defect that is important in determining whether or not a tree is dangerous.

If you think the tree might be diseased please report it. Ash dieback is a particular issue in Greater Manchester.

Please also be aware that bats are a protected species and often live in dead/hollow trees. There is more information in this Guidance on Bats leaflet.

Here are some common things that may render a tree dangerous:

  • If a tree suddenly develops a lean when previously it was upright.
  • Extensive decay is present in the main stem or larger branches.
  • Large broken branches are hanging in the crown of the tree.
  • Branches or branch forks are split and unstable due to failure or high winds.
  • The tree has fallen or part fallen.
  • Fungal fruiting bodies are present on the tree or around the base of the stem.
  • The tree is clearly dead.
  • The tree has severe dieback and appears stag headed.
  • There is a large amount of deadwood over 50mm in diameter throughout the crown

If you think one of the council's trees is dangerous please report it immediately using our online form.