All sorts of dangers for our plants lurk in the garden. One of the most common diseases is sooty mold, which is an infection caused by various fungal pathogens. Read how to get rid of the disease quickly.
What is sooty mold and how can you combat it?
Sooty mold is a fungal disease caused by ascomycetes and occurs as a result of pest infestation such as aphids, scale insects or mealybugs. The fungi feed on honeydew, the sweet secretions of these pests. In order to combat sooty mold, the pest infestation that causes it should be eliminated.
- Sooty mold is a fungal disease.
- This always occurs as a result of a pest infestation.
- The ascomycetes that cause sooty mold feed on honeydew, the sweet secretions of plant pests.
- The fungal disease itself does not need to be combated, but the pest infestation that causes it does.
What is sooty mold?
Sooty mold is a plant disease caused by various types of ascomycetes, which always occurs in connection with a pest infestation. The sooty mold fungi feed on the sweet, sticky excretions, the so-called honeydew, from aphids, scale insects, mealybugs and other pests. The pathogen does not attack the leaves of the affected plant directly - after all, it does not feed on them, but on honeydew - but the black coating impairs photosynthesis. In addition, fungi and plaque clog the plant's leaf pores.
Tip
The disease often occurs on houseplants, which are weakened, especially in winter, and are therefore at risk of pest infestation.
Is star sooty mold the same as sooty mold?
Star sooty mold occurs more frequently in humid weather
Star sooty mold is also a plant disease caused by ascomycete fungi, but it primarily occurs on outdoor garden plants. This disease, which you can recognize by the irregularly black spotted leaves that later yellow and massively fall off, occurs primarily in damp weather. Plants whose leaves cannot dry properly after watering or after rain are particularly at risk. In contrast to sooty mold, the black mold fungus does not feed on honeydew, which is why the infection occurs independently of a pest infestation.
Distinguish between sooty mildew and star sooty mildew
Use the information in the following table to help you distinguish between diseases.
| Sootdew | Star sooty dew | |
|---|---|---|
| pathogen | various mushrooms | Diplocarpon rosae |
| Synonyms | Blackness Disease | Black spot disease |
| Particularly endangered plants | no specific plants (since these fungi do not feed on plants but on honeydew) appear in the wake of honeydew-producing pests | especially roses, oleander and laurel, but also other plants |
| malicious image | sticky deposits on the leaves that are covered with a blackish, wipeable layer | initially star-shaped, black-brown, round spots, leaves yellow and fall off |
| Cause | Pest infestation, especially by aphids and other plant lice | Fungal spores that spread on the leaves mainly through rain or irrigation water |
Fighting sooty mold successfully
The faster you act, the better the chances of recovery
To successfully combat sooty mold, you must first get rid of the pests. In contrast to sooty mold, the use of insecticides or fungicides is not necessary here, as the fungus dies without available honeydew. And this is how it works:
- Isolate the affected/diseased plant from the others (if possible).
- Cut off heavily infested plant parts with sharp and clean scissors (€14.00 on Amazon).
- Fight the pests with suitable home remedies.
- Home-made sprays based on soapy water or plant broths (e.g. horsetail, tansy) are suitable for this purpose.
- Wipe the black fungal coating from the leaves with a damp, soft cloth.
- Repeat the treatment if necessary.
Tip
In contrast to sooty mold, star sooty mold is much more stubborn and difficult to combat. Prevent infection by regularly topping endangered plants with horsetail tea and watering them with nettle manure.
