Like any other (room) plant, the popular yucca - which is often incorrectly sold in stores under the term yucca "palm" - is occasionally attacked by pests. Not only are spider mites and various plant lice found, so-called gall mites are also very attractive to palm lilies. An infestation with these tiny pests is difficult to detect because the animals do not form galls on yuccas.
How do you fight gall mites on the yucca palm?
If you have a yucca gall mite infestation, early detection is crucial in order to treat the plant with plant protection products containing rapeseed oil or sulfur. Severe damage requires pruning and disinfection of the cut surfaces with tree resin or cinnamon/charcoal powder.
Identifying gall mites
Instead, the damage looks very similar to an infestation with mildew. Leaves and shoots are covered with a whitish layer, so many plant lovers initially think of a fungal disease and take appropriate countermeasures - which of course don't work, after all they are pests. Gall mites are tiny and can be found on many plants, especially woody plants. The formation of so-called galls is typical, but these are completely absent on Yuccas.
Successfully fight gall mites
A gall mite infestation leads to deformation and discoloration of the leaves on the plant in question, although the damage is usually mainly of a visual nature and has little negative impact on the host plant - unless a fungus is added as a result of the mite infestation. These find welcome entry points in the numerous tiny punctures in the leaves of the yucca. Gall mites, provided they are detected in good time, can be combated very well with plant protection products based on rapeseed oil or sulfur (€29.00 on Amazon). However, it is important to act quickly to avoid causing too much damage. If you want to be on the safe side: Sulfur-containing pesticides usually also help against mildew.
Often only a radical pruning helps
Gall mites are difficult to recognize and have therefore often caused serious damage to the leaves of the yucca. These look unsightly, but once infected they will no longer regenerate. In such a case, the only thing that helps is a pruning, even if it has to be radical. Fortunately, yuccas usually tolerate such measures very well and will sprout again even if you have only left part of the trunk standing.
Tip
If you want to cut back the infected yucca, apply tree resin to larger cut areas. Smaller ones, on the other hand, can be sprinkled with cinnamon or charcoal powder and disinfected in this way.
