Even very good care cannot always prevent fungal spores from spreading on the thuja and sometimes causing considerable damage to the tree of life. However, a he althy tree can usually cope well with an infestation. But there are also fungal diseases that cause the entire hedge to die.
What to do if the thuja is infected with fungus?
To combat fungal infestation on thujas, cut off infected shoots generously and dispose of them in household waste. A fungicide can help with Armillaria mellea infestation in the early stages. As a preventive measure, Thujas should be watered in the morning and thinned out occasionally to improve air circulation.
Fungal diseases of thuja
Four species of fungi attack the Thuja:
- Pestalotiopsis funerea
- Didymascella thujina
- Kabatina thujae
- Armillaria mellea (Hallimasch infestation)
Instinct death
The shoot death is caused by Pestalotiopsis funerea. Symptoms of an infestation are brown discoloration of the tip, which slowly spreads to the entire shoot. Later, black spots form, the shoot dries up and dies.
Needle and Scale Tan
Didymascella thujina and Kabatina thujae lead to browning of the needles and scales, with Kabatina thujae mainly affecting young leaves and tips. Initially, the symptoms of the infestation appear as small spots on needles and scales. They continue to spread and lead to the death of the entire shoot.
Thuja dying
Armillaria mellea is responsible for the dreaded Thuja dieback. This mushroom is characterized by a white network that can be found between the bark and wood. The thuja dies very quickly after an infestation and can no longer be saved.
What to do if the thuja is infected with fungus?
If a mild fungal infestation is detected in good time, it helps to cut off the affected shoots generously and dispose of them with household waste.
If the arborvitae hedge suffers from Armillaria mellea, you can try to combat the fungus with a fungicide. This is administered according to the instructions on the packaging. However, control is only successful if the fungal infestation is detected in the early stages.
Prevention of fungal infestation of thuja hedges
Fungal spores particularly like to spread on the tree of life when it is damp. Therefore, water in the morning if possible so that the thuja can dry out during the day. Avoid wetting the leaves and trunk.
To improve air circulation in the hedge, carefully thin out the trees occasionally. Cut out dry and cross-growing branches.
Tip
Infested with fungi, Thuja cuttings never belong in the compost. They are disposed of with household waste or – if possible – burned immediately in the garden.