- What diseases make the shoots of thuja turn black?
- Black needles due to manganese deficiency
- Treat manganese deficiency in Thuja hedge
- Fungal attack turns needles dark
As soon as the needles of the thuja change colour, this is an indication for the gardener that something is wrong with the tree of life. Mistakes in care are often responsible for the shoots turning brown, yellow or even black. What diseases turn thuja needles black?
If the needles of the thuja turn black, the tree of life is usually lacking in nutrients
What diseases make the shoots of thuja turn black?
Thuja black shoots are not diseases. They are almost always a sign that the Tree of Life is lacking in something, namely manganese.
Occasionally, a fungal attack can also cause very dark needles.
Black needles due to manganese deficiency
Manganese is usually found in sufficient quantities in the substrate. In unfavorable site conditions, however, the tree of life cannot absorb sufficient manganese through the roots, for example in the case of:
- compacted soils
- waterlogging
- too acidic substrate
An unfavorable location for the hedge is where the soil is too damp or even waterlogged. The tree of life needs more manganese on very acidic soil 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 value should then definitely be increased.
Treat manganese deficiency in Thuja hedge
After the appearance of black needles on the tree of life, first loosen the soil and ensure better drainage as much as possible.
Treat overly acidic soil with lime. This increases the pH value so that the hedge gets by with less manganese.
You can simply cut off the black shoots and dispose of them in the compost.
Fungal attack turns needles dark
If the needles of the thuja become dark brown or almost black, there may also be a fungal infestation. It occurs more often when the plants are very dense or the weather is generally very humid.
Cut off affected shoots generously and dispose of them in the household waste, not on the compost!
If the infestation is severe, use a broad-spectrum spray against fungal diseases. The temperatures should not be below 6 degrees.
tips
Before planting a hedge of thuja, you should work the soil well. Remove all thickening and create drainage for very solid soil. Heavy soils are loosened up by adding compost or sand.