The yew is a native, very resilient tree that rarely suffers from disease and even more rarely from fungal attack. If yellow needles appear on the yew, either pests or an unfavorable location are responsible. How can you prevent yellow needles on the yew tree?
Why does my yew tree have yellow needles and how can I prevent it?
Yellow needles on a yew tree are usually not the result of diseases, but rather due to unfavorable site conditions or pests such as scale insects. To prevent this, make sure you have an ideal location and use biological control methods when pests are infested.
Yellow needles of yew not due to diseases
If the yew tree gets needles that also fall off, it is usually not diseases that are to blame, but rather an unfavorable location or an infestation by pests, or more rarely by fungi.
Needle discoloration can usually be prevented if you grow the yew tree in a favorable location and care for it properly. Well-cared for yew trees can cope well with pest infestations.
An inconvenient location
Yew trees tolerate any location, including shade or direct sun. However, this only applies to older trees. Young yew trees suffer from strong sunlight and react to this with yellow or brown needles. This also happens in winter when the winter sun falls directly on the needles.
When planting, ensure you have an ideal location where the young plant will receive sufficient shade during midday.
The yellow needles caused by a poor location may not look pretty, but are not dangerous for the tree. The needles will be green again next year at the latest.
Pests on the yew tree cause yellow needles
Yellow needles can also be caused by pests. The scale insect is not very common but occasionally found on the yew tree. It is difficult to see with the naked eye. If ant trails run onto the tree, an infestation is likely.
If you suspect scale insect infestation on the yew tree, take the following control measures:
- Breaking the ant trails
- cut off infected branches
- if applicable. Insert parasitic wasps
- Insecticides are not effective!
Scale insects have a strong shell that chemical agents cannot penetrate. It is therefore better to rely on biological agents such as parasitic wasps (€13.00 on Amazon).
Tip
In winter, you should water yew trees on frost-free days if it has been dry for a long time. They suffer from excessive dryness, especially because the trees are very young and the roots do not yet protrude so deeply into the ground.