As long as she is healthy, she requires little nursing work. But if she gets sick, you have to act quickly. What diseases can star magnolia affect? How do you recognize them, how can they be combated and prevented?
What diseases can occur
Basically, the star magnolia is not very susceptible to disease. If the site conditions are right, it usually holds up well. With bad luck, for example, in adverse weather, mildew and leaf spots can mark the plant. In rarer cases, scab and fruit tree canker occur.
Powdery mildew on star magnolia
If your star magnolia is affected by powdery mildew, you can tell by the grey-white to yellowish spots on its leaves. Sometimes the shoot tips are curled up. This is powdery mildew, where fungal spores are the culprit.
If you have a powdery mildew infestation, there are a number of things you can do. Either you cut away the affected parts of the star magnolia (does not tolerate radical pruning) or you spray the affected parts of the plant with nettle broth or a saline solution. In general, it is advisable not to use chemical agents to combat the fungal pathogen.
Leaf spots on star magnolia
Leaf spot is caused by a bacterium called Pseudomonas. It prefers to attack the leaves and petals of the star magnolia. An infestation can be recognized by black, more angular than round spots on the leaves or petals. At a later stage, holes appear. Eventually the leaves fall off.
To get rid of the bacterium, you should completely remove and safely dispose of all foliage from the plant in the fall. Pseudomonas hibernates in the leaves to cause trouble again next year…
Why is the star magnolia ailing?
There can be several reasons why a star magnolia is affected by diseases. These include, among others:
- Transplanting in the wrong place and at the wrong time
- nutrient deficiency
- Too alkaline soil pH
- lack of water
- stress
- Too small planting distance to other plants
- windless location
- too dense crown
To prevent this, you should choose a suitable location for the star magnolia from the outset. In addition to penumbra, an airy location is important. Thin out the crown regularly so that water on the leaves can dry quickly.
tips and tricks
Star magnolias are sensitive to drought. This weakens them and makes them more susceptible to disease. Prevent this by mulching the root area.