White spots on the upper leaf surface of the palm are common. In addition to parasitic damage, i.e. damage caused by harmful insects, care errors can also be responsible for the unsightly discolouration.
Calcareous water can leave white spots on palm leaves
Calcareous water
Palm trees need a certain level of humidity to thrive. Frequent wetting of the fronds with a sprayer is therefore advisable. However, some plant lovers use unfiltered tap water for this, which contains a lot of lime in some regions. This remains after drying as an ugly white spot on the foliage.
remedy
In areas with hard tap water you should only use the palm
- distilled
- filtered
- or stale
mist water.
scale insects
These lice secrete a secretion that covers the insects like a protective shield, protecting them from the weather and predators. The sap-sucking animal does not move, but sits under its shield together with a large number of eggs. White discoloration of the leaves appears at the puncture sites, and fungal infections (sooty mildew) often occur as a result.
combat
Scale insects are very stubborn parasites that like to hide in hard-to-reach areas of the palm tree. Follow these steps:
- Isolate plant immediately.
- First, shower off with a strong jet of water.
- Then apply a systematically acting poison in stick form or as a spray.
Contact poisons unfortunately prove to be ineffective against scale insects, since the pests are excellently protected by their hard back shell.
Mealybugs (meal lice)
These white-colored harmful insects, which also belong to the scale insects, sit almost motionless on the leaves and look like white spots. Viewed with a magnifying glass, they resemble tiny cotton balls and are therefore relatively easy to identify.
If there is a slight infestation, you can remove it by showering off the palm. It is then also possible to fight with pure alcohol, which is applied directly to the pests with a cotton swab. In the event of a severe infestation, you should always treat the palm with a suitable insecticide.
tips
It is often recommended to scrape off large colonies of scale insects with a knife. However, this only makes sense for isolated animals. The scraping involves the risk of spreading the many eggs and larvae that also live under the shields throughout the plant. This will unintentionally spread the plague.