If you find white, woolly or off-white coverings on the palm trees, these are usually pests. Powdery mildew as with other plants is rather rare. Since the animals that suck plant sap can massively damage the palm tree, you should always treat it with a suitable agent.
Lice are often the cause of the white coating on palm leaves
Identify and fight mealybugs
The animals, also known as mealybugs, reach a length of one to five millimeters. Their bodies are covered with white, woolly hairs that make the animals look like tiny cotton balls.
symptoms of infestation
- Initially small, later merging white spots on the fronds.
- The leaves turn yellow and dry up.
- The lice secrete honeydew, which can subsequently cause an infestation with sooty mold (reddish-brown spots).
combat
Isolate the palm immediately to prevent the spread of the pests. Apply a plant protection product containing neem oil, which must act directly on the lice. Furthermore, the harmful insects can be fought very well with plant protection sticks, which are stuck into the ground. The active ingredients get directly into the leaves via the sap flow, the mealybugs absorb them and die. In the winter garden you can contain the plague of lice with the larvae of the Australian ladybird.
Cause gall mites
These often settle on the yucca palm, more rarely on real palm trees. At 0.2 millimeters in size, the little creatures are so small that they can hardly be seen with the naked eye.
symptoms of infestation
The pests leave a whitish coating on the leaves that is strongly reminiscent of powdery mildew. The suction activity creates tiny hairs that give this impression.
combat
Specialist shops have various sprays available that, when used correctly, quickly kill the animals. In any case, do not only spray the upper side of the leaf, but also the underside of the leaf and the leaf axils, as the pests like to hide here.
tips
Pest infestation can often be prevented with good care. Spray the palm daily with lukewarm, lime-free water. Mix some seaweed juice into the splash water once a week. This strengthens and strengthens the plant.