In recent years, the bark of apple trees has increasingly turned red in some regions. However, this does not necessarily have to be a symptom of a tree-endangering disease.

A red discoloration on the tree trunk can have different causes

In principle, the red color alone is not a sufficient indicator for an accurate statement on the state of health of an apple tree. While red discoloration occurs over a large area, reasons such as the egg clutches of blood lice can be ruled out, other phenomena and fungal diseases can still occur
be the reason for a conspicuous red coloring on the trunk. Take a close look at the bark and determine whether the red coloring is only spotty or rather flat and thin. While the former would speak for the red pustular fungus, the latter rather indicates so-called green algae.

The red pustular fungus is not to be trifled with

The discoloration caused by the red pustular fungus initially only appears as inconspicuous spots on the stem bark. The sac fungus is a member of the order Crustacea and is quite a serious threat to tree health. If left unchecked, he will soon begin to sprout his fruiting bodies on more and more parts of the apple tree trunk. Fungicides are only insufficiently effective against it, even in commercial cultivation. Since the fungus saps the strength of the apple tree, affected areas should be cut back into the healthy wood and the material should be disposed of away from the apple trees. The following work steps are necessary:

  • Determined by a garden specialist
  • Remove the affected branches and trunk
  • proper disposal of the infested wood
  • Wound care as protection against renewed fungal infestation

The harmless explanation: green algae

It sounds a little hard to believe, but in fact improved air quality and fewer pollutants in the air are responsible for the fact that more and more trees in the garden are now turning red in the form of so-called green algae (Trentepohlia umbrina). Although this coloring may seem a bit dangerous at first glance, green algae on the stem bark are not classified as a disease, as they do not damage the tree in any way. If you want to remove the algae for visual reasons, carefully dispose of the parts of algae removed with a brush, otherwise they can spread all the more to nearby tree trunks.

tips and tricks

If the red discoloration of the tree bark occurs together with stunted growth and other symptoms, a problematic location with the wrong soil can also be the reason.

Category:

Trees