Content
- Which diseases color the Thuja black?
- By what diseases are the shoots of the Thuja black?
- Black needles due to manganese deficiency
- Treat manganese deficiency of Thuja hedge
- Fungus stains needles dark
- Tips
When the needles of the thuja turn black, the tree of life usually lacks nutrients
Which diseases color the Thuja black?
As soon as the needles of the thuja discolour, this is an indication to the gardener that something is wrong with the Tree of Life. Care mistakes are often responsible for turning the shoots brown, yellow or even black. Which diseases stain the needles of the Thuja black?
By what diseases are the shoots of the Thuja black?
Thuja black shoots are not diseases. They are almost always an indication that the tree of life lacks something, manganese.
Occasionally, fungal attack can cause very dark needles.
Black needles due to manganese deficiency
Manganese is usually present in the substrate in sufficient quantities. However, under unfavorable site conditions, the tree of life can not absorb enough manganese via the roots, for example:
An unfavorable location for the hedge is where the soil is too humid, or even forms waterlogging. On very acidic soils, the tree of life needs more manganese than on a pH neutral soil.
Have the substrate examined in the laboratory. If the pH is below 6, the soil is too acidic. The pH should then be increased necessarily.
Treat manganese deficiency of Thuja hedge
After the appearance of black needles on the tree of life, first loosen the soil and provide as much as possible for a better drainage.
Treat to acid soils with lime. This increases the pH so that the hedge uses less manganese.
You can simply cut off the black shoots and dispose of them in the compost.
Fungus stains needles dark
If the needles of the Thuja become dark brown or almost black, there may also be a fungal attack. It occurs more often when the plants are very dense or the weather is generally very humid.
Generously cut off any infested shoots and dispose of them in the household waste, not on the compost!
In case of heavy infestation, use a broad-spectrum spray against fungal diseases. The temperatures should not be below 6 degrees.
Tips
Before you plant a hedge of thuja, you should work the soil well. Remove all thickening and apply drainage for very solid soil. Heavy soils are loosened up by the addition of compost or sand.