Content
- Common diseases in magnolia
- Leaf spot
- Fighting leaf spot disease
- mildew
- Prevent and fight mildew
- pest infestation
- Tips & Tricks
Common diseases in magnolia
Healthy magnolias are quite resistant to pest infestation and other diseases. It is therefore always a symptom that your magnolia is weakened and prone to being affected by inappropriate location or care. Especially the following diseases are common in weakened magnolias.
Leaf spot
The leaf blotch disease is caused by Pseudomonas bacteria, which are mainly in raindrops or rainwater. It occurs especially in warm, but humid weather and is characterized by black, with a yellowish yard surrounded spots or even holes on the leaves. As a result, infested shoots die. Even with deciduous Magnolia species this very widespread plant disease is a problem because the bacteria overwinter in the shoots and often cause frost damage.
Fighting leaf spot disease
Leaflet disease is best combated by prevention: it is important that the crown of the magnolia is not too dense, but lets in enough light and air. The leaves should always be able to dry quickly, which is why you should never pour in the summer from above (especially not with rainwater), but only directly at the roots. In case of infestation, the affected parts of the plant should be removed as soon as possible.
mildew
There are two different types of powdery mildew, both of which initially show a whitish or greyish surface on the leaves. Later, the leaves turn brown and fall off. This plant disease is caused by Erysiphaceae mushrooms.
Prevent and fight mildew
Mildew can be controlled very well with a garlic or lactic acid. For the latter, mix one part of whole milk with nine parts of water and sprinkle the magnolia over a period of several days. In case of heavy infestation often only fungicides help. Infested shoots and leaves should be removed immediately as mildew spreads very quickly.
pest infestation
Weakened magnolias are often attacked by the white fly or by scale insects whose excretions promote fungal diseases (eg with the soot dew) and an infestation with aphids. The roots can be eaten by larvae or subterranean caterpillars, damaging the tree. In particular, voles and Dickmaul weevil larvae like to indulge in the juicy magnolia roots.
Tips & Tricks
Prevention is better than cure, so you can help endangered magnolias with a special fungicide fertilizer to get rid of annoying pest spirits quickly. By the way, even dried coffee grounds should help.