Tree Alert Page Topper

Taking good photos for your Tree A!ert reports

Pictures of an affected tree can be more useful than a lengthy written description of the symptoms which it displays but only if the photos are taken well and they illustrate the correct range of features.

How to take your photos:

  • Make sure that the pictures are large enough to illustrate the point that you intend to show (anything less than 800 x 600 pixels will usually be too small) but are not so large that it is difficult to handle and store them (a photo of 2400 x 1800 pixels, equating to a good quality JPEG image of around 1 Mb in size, is a reasonable upper limit). If your camera or phone has a sensor of more than 5 megapixels and is set to capture images at maximum resolution and quality then your photos are likely to be larger than necessary. There are many software packages (some of which may already be installed on your computer) as well as free-use websites which will allow you to resize pictures easily before you upload them.
  • Take your pictures in the best possible natural light, but use flash if needed, to avoid both "camera shake" (blurry pictures) and photos which are too dark to illustrate the features that you want to show.

What to photograph:

  • Although it's tempting to concentrate on taking detailed images of the symptom(s) which the tree displays, it's just as important to show the entire tree and its surroundings (the tree in context) and to how the symptoms are distributed on the affected parts of the tree (the symptom in context) as it is to illustrate the symptom up close (the detailed symptom). We recommend that you take several images of each type and upload only the best one in each category (a total of 3 images). Here are images of two different trees suffering from different problems which illustrate the type of image that we're looking for in each category (each photo is accompanied by a description of what can be seen by careful examination of the picture):

Tree in context

Should show the entire tree and its immediate surroundings. This provides information on the nature of the site, the conditions in which the tree is growing, whether any other plants in the vicinity are showing signs of disease or damage, and a range of other factors which may have had an impact on the health of the tree. It may also provide an overall indication of how symptoms are distributed on the crown, stem or stem base.

Conifer foliage disease - a young pine growing well and sheltered by larger trees nearby. Short but healthy ground vegetation. Browning of needles is confined to the base of the crown.


Broadleaf root disease - a large beech tree with a relatively thin crown which has turned yellow prematurely. Situated adjacent to a road which increases the danger to public safety if the tree falls.

Symptom in context

Should illustrate how the symptom is distributed locally on the affected part(s) of the tree. This type of image helps to indicate the severity of the symptom(s) and which part(s) of the tree may be affected by a problem (e.g. browning of leaves may be the result of damage to the shoot or branch which holds them rather than direct damage to the leaves themselves by a foliar pest or pathogen). It may also help to identify the species of tree concerned if there is any uncertainty about this.

Conifer foliage disease contd. - browning of foliage on this tree is confined to the older needles further back on the branch. The branch is bare below whilst new needles at the tip of the branch are healthy.


Broadleaf root disease contd. - at least five clumps of large fungal fruiting bodies are growing from the roots at and near the stem base. They are distributed around at least half the circumference of the stem.

Detailed symptom

Should show the fine detail of the symptom as clearly as possible. This type of image helps to indicate the small-scale distribution of dead and live tissue and any associated discolouration on the affected part of the tree or may illustrate the pest of pathogen itself. Where the symptom is variable, it can be useful to include several affected parts (such as leaves or needles) in a single picture. Placing an object in the frame to indicate the scale at which the image was taken can sometimes be useful.

Conifer foliage disease contd. - affected needles are all brown at their tips but generally green at their bases. There is a sharp dividing line between brown and green tissue. Red bands are visible on some needles and dark dots are visible within these bands.


Broadleaf root disease contd. - the fruiting bodies are large (see pound coin on top of lower "frond"). They are tiered and chestnut-brown above with a lighter underside. There are no gills on the under-surface of the fruiting bodies but minute pores are present.