With good care and a suitable location, lice and other pests have a hard time because the yucca (and of course other houseplants) then have enough defenses. However, weakened plants cannot defend themselves and are therefore defenseless against infestation. So if you notice any pathological changes, especially in the leaves of the yucca, you should react quickly and appropriately.
Which pests attack the yucca palm and how can you combat them?
Pests that attack the yucca palm are plant lice (aphids, scale insects, mealybugs), gall mites and spider mites. A spray treatment with tea tree oil and water solution, spraying with rinse water for gall mites and increasing the air humidity for spider mites are suitable for combating them.
First indications of a pest infestation and its causes
In many cases, a pest infestation on the yucca can only be recognized by sticky leaves or leaf discoloration or deformation. If the tree “sticks”, it is most likely plant lice, often scale insects. A white, mealy coating, on the other hand, can be an indication of powdery mildew (which is rare in Yucca), but also of gall mites. Brown spots or similar, on the other hand, are due to fungi, but are often also due to damage caused by leaf sap-sucking pests such as spider mites. Usually only plants weakened by incorrect care or a location that is too dark or too dry are affected.
Common pests – and how to fight them
Check the yucca regularly for animal pests. Many like to sit on the tips of shoots, young leaves, but also on the undersides of the leaves and the leaf axils. Feel free to use a magnifying glass.
Plant lice
Plant lice include aphids, scale insects and mealybugs. These little animals often make themselves known through a sticky coating on the leaves. These are the excreta known as “honeydew”. All lice can be treated well with a spray treatment, for which you mix 10 drops of tea tree oil (or lavender oil for aphids) with a liter of warm water.
Gall mites
An infestation with gall mites on the yucca can easily be confused with powdery mildew, as it appears as a white and mealy coating. In contrast to other plants, this mite does not form galls on the yucca, which is why it is easier to control here. Spraying with rinse water helps in many cases.
Spider mites (Red Spider)
If there are small light spots on the top of the leaf and perhaps a fine web underneath on the yucca, these are spider mites. These only occur when the air in the room is too dry, which is why increasing the humidity (or moving the affected plant out) can help. Spray the plant with a tea tree oil-based solution, although in stubborn cases you can also use neem preparations.
Tip
Pests can also be brought into the house through newly purchased plants that are already infested. Since an infestation is not always obvious at first glance, it is best to quarantine the new arrivals in a cooler, not directly sunny place. Only move them to their final location after a few days.
