Olives are very easy to care for and basically extremely robust trees that are rarely attacked by pests, fungi or diseases. Such an infestation is usually due to improper care, especially in winter.
Which pests attack olive trees in Germany?
Common pests on olive trees in Germany are scale insects, mealy bugs, spider mites and aphids. However, through proper wintering, regular watering and the use of sterilized plant substrate, infestation and damage can be largely avoided.
Olive fruit fly rare in Germany
Feared in the growing countries, but rather rare in this country - i.e. H. not yet known – is the olive fruit fly. This pest, which specializes in olives, lays its eggs in the unripe fruits and can not only cause damage to the tree itself, but can also transmit the bacterium Pseudomonas syringae. This bacterium causes the incurable olive cancer, which is noticeable through heavy cell proliferation on the branches and trunk. Other pests that are feared in traditional growing countries have not yet been detected in this country.
Frequent infestations with scale insects and mealybugs
Instead, German olives are often plagued by stubborn scale insects and mealybugs, especially if the affected olive did not overwinter optimally. The plant lice love warmth and prefer to attack weakened plants. As a result, indoor olives or olives in winter dormancy are the perfect victims. The best way to prevent plant lice is to overwinter the olives outdoors or in a cool and bright location at a maximum of 10 °C. Light frost kills the pests. In summer, it is best to place infected olives in the full sun - and separate them from other plants so that the infestation does not spread.
Spider mites and aphids are also common
Another sign of incorrect overwintering is an infestation with spider mites. These very widespread plant pests often come from insufficiently disinfected potting soil. They are located on the underside of the leaf and can be identified by the white web that gives them their name. Spider mites love dryness - just as dry indoor air as dry soil.
Combating spider mites
You can get rid of spider mites quite easily:
- water small olive trees vigorously and then put them in a plastic bag
- leave the tree like this for a few days
- a humid climate develops in the bag, which causes the spider mites to die
- larger trees or alternatively spray them all around with nettle broth
Aphids are also increasingly found on the underside of leaves or on young shoots. Since this pest causes leaves and shoots to wither, treatment makes sense. Spraying with nettle decoction also helps here.
Making nettle decoction
- Pick about 250 grams of nettle leaves - don't forget gloves!
- Roughly chop them.
- Soak the nettles in two liters of water for 24 hours.
Spray the affected plants with the undiluted solution for several days in a row.
Tips & Tricks
Pests can be prevented by overwintering your olive according to its needs, not keeping it too dry and also only using sterile soil for planting.
