Leaf spot disease can cause significant damage to lemon balm and lead to severe yield losses. It is therefore important to recognize the fungal disease early and treat it correctly. In this article you will find all the important information about it.
How do I combat leaf spot on lemon balm?
Isolate your lemon balm as soon as you notice leaf spot. This will prevent the fungal pathogen from spreading. Cut back affected plant parts generously and dispose of them in organic waste, not in compost. If the infestation is very severe, the plant must be completely disposed of.
How does leaf spot manifest itself in lemon balm?
In leaf spot disease,numerous dark spots first appear on the lower leaves of lemon balm, often with a purple edge. The upper leaves often only have small brownish dots.
Using a magnifying glass, you can see the so-called spore containers in the form of tiny black dots on the spots.
If there is a severe infestation with the fungal pathogens that cause them, the leaf spots coalesce so that the leaves dry out completely, die and tear.
How does leaf spot occur in lemon balm?
Triggers of leaf spot disease on lemon balm are ascomycetes from the genusSeptoria melissaeLike other mushrooms, they feel particularly comfortable in damp weather. That's whypersistent leaf wetness caused by long periods of rain, incorrect watering or too close planting distances is the main cause of the disease.
Furthermore, unbalanced fertilization, which results in a nutrient deficiency or excess, as well as a location that is too shady, promote the spread of pathogens.
How do I prevent leaf spot on lemon balm?
To prevent leaf spot on lemon balm, you should pay particular attention to adequate care. Specifically this means:
- always only water the root area, never the leaves
- Maintain sufficient planting distance for good ventilation so that the leaves can dry quickly
- fertilize in a balanced way
- choose a bright location
Tip
Disinfect secateurs before and after pruning
To prevent the transmission of Septoria fungi and other pathogens to your various plants, you should thoroughly clean and disinfect the secateurs with which you cut back the affected parts of the lemon balm plant both before and after use.
