Leaf spot disease
the Leaf spot disease is caused by Pseudomonas bacteria, which are mainly found in raindrops or Rainwater frolicking. It occurs mainly in warm but humid weather and is characterized by black spots surrounded by a yellowish halo or even holes on the leaves. As a result, the affected shoots die off. This very widespread plant disease is also a problem with deciduous magnolia species, because the bacteria overwinter in the shoots and often cause frost damage.
also read
- Recognize and fight common diseases of the maple - this is how it works
- Common diseases in hawthorn and how to combat them
- What is my ash maple suffering from? - Overview of common diseases
Combat leaf spot disease
The best way to combat leaf spot disease is through prevention: It is important that the crown of the magnolia is not too dense, but that it lets in enough light and air. The leaves should always be able to dry off quickly, which is why you should never water from above (especially not with rainwater) in summer, but only directly at the roots. In the event of an infestation, the affected parts of the plant are
remove as soon as possible.mildew
There is two different types of powdery mildewboth of which initially appear as a whitish or greyish coating on the leaves. Later the leaves turn brown and fall off. This plant disease is caused by Erysiphaceae fungi.
Prevent and control powdery mildew
mildew can be combated very well with a garlic stock or lactic acid. For the latter, mix one part whole milk with nine parts water and spray the magnolia over a period of several days. In the case of severe infestation, only fungicides can often help. Infested shoots and leaves should be removed immediately, as powdery mildew spreads very quickly.
Pest infestation
Weakened magnolias are often caused by the Whitefly or by scale insects infested, the excretions of which are fungal diseases (e. B. with the soot dew fungus) and an infestation with aphids. The roots, on the other hand, can be eaten by larvae or caterpillars living underground and thus damage the tree. Voles and vine weevil larvae in particular like to feast on the juicy magnolia roots.
Tips & Tricks
Prevention is better than cure, which is why you can help endangered magnolias with a special fungicide fertilizer to get rid of annoying nuisances quickly. By the way, dried coffee grounds should also help.